Как сделать смену слайда каждые 15 секунд?

Question

Ибрахим Тубаев @ibrakhim20070618

HTML
CSS

Как сделать смену слайда каждые 15 секунд?

Здравствуйте! Есть небольшой сайт-слайдер. Как сделать смену каждого слайда каждые 15 секунд?
Вот HTML-код:

<!DOCTYPE html>
<html >
<head>
  <meta charset="UTF-8">
  <title>Акции 2 отряда</title>
  
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/meyer-reset/2.0/reset.min.css">

  <link rel='stylesheet prefetch' href='https://fonts.googleapis.com/css?family=Montserrat:400,700'>
<link rel='stylesheet prefetch' href='https://fonts.googleapis.com/css?family=Poppins:400,700'>

      <link rel="stylesheet" href="css/style.css">

  
</head>

<body>
  <div class="slider__warpper">
  <div class="flex__container flex--pikachu flex--active" data-slide="1">
    <div class="flex__item flex__item--left">
      <div class="flex__content">
        <p class="text--sub">Pokemon Gen I</p>
        <h1 class="text--big">Pikachu</h1>
        <p class="text--normal">Pikachu is an Electric-type Pokémon introduced in Generation I. Pikachu are small, chubby, and incredibly cute mouse-like Pokémon. They are almost completely covered by yellow fur.</p>
      </div>
      <p class="text__background">Pikachu</p>
    </div>
    <div class="flex__item flex__item--right"></div>
    <img class="pokemon__img" src="https://s4.postimg.org/fucnrdeq5/pikachu.png" />
  </div>
  <div class="flex__container flex--piplup animate--start" data-slide="2">
    <div class="flex__item flex__item--left">
      <div class="flex__content">
        <p class="text--sub">Pokemon Gen IV</p>
        <h1 class="text--big">Piplup</h1>
        <p class="text--normal">Piplup is the Water-type Starter Pokémon of the Sinnoh region. It was introduced in Generation IV. Piplup has a strong sense of self-esteem. It seldom accepts food that people give because of its pride.</p>
      </div>
      <p class="text__background">Piplup</p>
    </div>
    <div class="flex__item flex__item--right"></div>
    <img class="pokemon__img" src="https://s4.postimg.org/sa9dl4825/pilup.png" />
  </div>
  <div class="flex__container flex--blaziken animate--start" data-slide="3">
    <div class="flex__item flex__item--left">
      <div class="flex__content">
        <p class="text--sub">Pokemon Gen III</p>
        <h1 class="text--big">Blaziken</h1>
        <p class="text--normal">Blaziken is the Fire/Fighting-type Starter Pokémon of the Hoenn region, introduced in Generation III. Blaziken is a large, bipedal, humanoid bird-like Pokémon that resembles a rooster.</p>
      </div>
      <p class="text__background">Blaziken</p>
    </div>
    <div class="flex__item flex__item--right"></div>
    <img class="pokemon__img" src="https://s4.postimg.org/6795hnlql/blaziken.png" />
  </div>
  <div class="flex__container flex--dialga animate--start" data-slide="4">
    <div class="flex__item flex__item--left">
      <div class="flex__content">
        <p class="text--sub">Pokemon Gen IV</p>
        <h1 class="text--big">Dialga</h1>
        <p class="text--normal">Dialga is a Steel/Dragon-type Legendary Pokémon. Dialga is a sauropod-like Pokémon. It is mainly blue with some gray, metallic portions, such as its chest plate, which has a diamond in the center. It also has various, light blue lines all over
          its body.</p>
      </div>
      <p class="text__background">Dialga</p>
    </div>
    <div class="flex__item flex__item--right"></div>
    <img class="pokemon__img" src="https://s4.postimg.org/43yq9zlxp/dialga.png" />
  </div>
  <div class="flex__container flex--zekrom animate--start" data-slide="5">
    <div class="flex__item flex__item--left">
      <div class="flex__content">
        <p class="text--sub">Pokemon Gen V</p>
        <h1 class="text--big">Zekrom</h1>
        <p class="text--normal">Zekrom is a Dragon/Electric-type Legendary Pokémon. It is part of the Tao Trio, along with Reshiram and Kyurem. Zekrom is a large, black draconian Pokémon that seems to share its theme with its counterpart, Reshiram. It has piercing red eyes and
          dark gray to black skin that seems to be armor-like.</p>
      </div>
      <p class="text__background">Zekrom</p>
    </div>
    <div class="flex__item flex__item--right"></div>
    <img class="pokemon__img" src="https://s4.postimg.org/malmhgn9p/zekrom.png" />
  </div>
</div>

<div class="slider__navi">
  <a href="#" class="slide-nav active" data-slide="1">pikachu</a>
  <a href="#" class="slide-nav" data-slide="2">piplup</a>
  <a href="#" class="slide-nav" data-slide="3">blaziken</a>
  <a href="#" class="slide-nav" data-slide="4">dialga</a>
  <a href="#" class="slide-nav" data-slide="5">zekrom</a>
</div>
  <script src='https://code.jquery.com/jquery-2.2.4.min.js'></script>

    <script src="js/index.js"></script>

</body>
</html>

Вот CSS код:

*, *:before, *:after {
	-webkit-box-sizing: border-box;
	-moz-box-sizing: border-box;
	box-sizing: border-box;
}

.slider__navi {
	position: absolute;
	top: 50%;
	right: 20px;
	transform: translateY(-50%);
	-webkit-transform: translateY(-50%);
	-moz-transform: translateY(-50%);
	-ms-transform: translateY(-50%);
	-o-transform: translateY(-50%);
	z-index: 999;
}

.slider__navi a {
	display: block;
	height: 6px;
	width: 20px;
	margin: 20px 0;
	text-indent: -9999px;
	box-shadow: none;
	border: none;
	background: rgba(0,0,0,0.2);
}

.slider__navi a.active {
	background: rgba(255,255,255,1);
}

body {
	position: relative;
	font-size: 100%;
	font-family: 'Montserrat', sans-serif;
	font-weight: 400;
	min-height: 100vh;
}

.flex__container {
	position: absolute;
	top: 0;
	left: 0;
	display: flex;
	display: -webkit-flex;
	display: -moz-flex;
	display: -ms-flex;
	-webkit-flex-flow: row wrap;
	-moz-flex-flow: row wrap;
	-ms-flex-flow: row wrap;
	-o-flex-flow: row wrap;
	flex-flow: row wrap; 
	-webkit-justify-content: flex-start;
	-moz-justify-content: flex-start;
	-ms-justify-content: flex-start;
	-o-justify-content: flex-start;
	justify-content: flex-start;
	height: 100vh;
	width: 100%;
	z-index: 1;
}

.flex__container.flex--active {
	z-index: 2;
}

.text--sub {
	font-size: 12px;
	letter-spacing: 0.5rem;
	text-transform: uppercase;
	margin-bottom: 40px;
}

.text--big {
	font-family: 'Poppins', sans-serif;
	font-size: 7.5em;
	font-weight: 700;
	line-height: 110px;
  margin-left: -8px;
}

.text--normal {
	font-size: 13px;
	color: rgba(255, 255, 255, 0.8);
	line-height: 22px;
	margin-top: 25px;
}

.text__background {
	font-family: 'Poppins', sans-serif;
	position: absolute;
	left: 72px;
	bottom: -60px;
	color: rgba(0,0,0,0.05);
	font-size: 170px;
	font-weight: 700;
}

.flex__item {
	height: 100vh;
	color: #fff;
	transition: transform 0.1s linear;
}

.flex__item--left {
	display: flex;
	display: -webkit-flex;
	display: -moz-flex;
	display: -ms-flex;
	align-items: center;
	-webkit-align-items: center;
	-moz-align-items: center;
	-ms-align-items: center;
	width: 65%;
	transform-origin: left bottom;
	transition: transform 0.1s linear 0.4s;
	opacity: 0;
	position: relative;
	overflow: hidden;
}

.flex__item--right {
	width: 35%;
	transform-origin: right center;
	transition: transform 0.1s linear 0s;
	opacity: 0;
}

.flex--preStart .flex__item--left,
.flex--preStart .flex__item--right,
.flex--active .flex__item--left,
.flex--active .flex__item--right {
	opacity: 1;
}

/* Piplup */

.flex--piplup .flex__item--left {
	background: #3e9fe6;
}

.flex--piplup .flex__item--right {
	background: #d3eaef;
}

/* Pikachu */

.flex--pikachu .flex__item--left {
	background: #f8d41f;
}

.flex--pikachu .flex__item--right {
	background: #f4ecc5;
}

/* Blaziken */

.flex--blaziken .flex__item--left {
	background: #f64f37;
}

.flex--blaziken .flex__item--right {
	background: #ffebcd;
}

/* Dialga */

.flex--dialga .flex__item--left {
	background: #476089;
}

.flex--dialga .flex__item--right {
	background: #ade8f7;
}

/* Zekrom */

.flex--zekrom .flex__item--left {
	background: #424242;
}

.flex--zekrom .flex__item--right {
	background: #a7bcbb;
}

.flex__content {
	margin-left: 80px;
	width: 55%;
	opacity: 1;
	transform: translate3d(0,0,0);
	transition: transform 0.2s linear 0.2s, opacity 0.1s linear 0.2s;
}

.pokemon__img {
	position: absolute;
	bottom: 20px;
	right: 15%;
	max-height: 40vw;
	opacity: 1;
	transform: translate3d(0,0,0);
	transition: opacity 0.43s 0.6s, transform 0.4s 0.65s cubic-bezier(0, 0.88, 0.4, 0.93);
}

/* Animate-START point */

.flex__container.animate--start .flex__content {
	transform: translate3d(0,-200%,0);
	opacity: 0;
}

.flex__container.animate--start .pokemon__img {
	transform: translate3d(-200px,0,0);
	opacity: 0;
}

/* Animate-END point */

.flex__container.animate--end .flex__item--left {
	transform: scaleY(0);
}

.flex__container.animate--end .flex__item--right {
	transform: scaleX(0);
}

.flex__container.animate--end .flex__content {
	transform: translate3d(0,200%,0);
	opacity: 0;
}

.flex__container.animate--end .pokemon__img {
	transform: translate3d(200px,0,0);
	opacity: 0;
}

Вот JS код:

$('.slide-nav').on('click', function(e) {
  e.preventDefault();
  // get current slide
  var current = $('.flex--active').data('slide'),
    // get button data-slide
    next = $(this).data('slide');

  $('.slide-nav').removeClass('active');
  $(this).addClass('active');

  if (current === next) {
    return false;
  } else {
    $('.slider__warpper').find('.flex__container[data-slide=' + next + ']').addClass('flex--preStart');
    $('.flex--active').addClass('animate--end');
    setTimeout(function() {
      $('.flex--preStart').removeClass('animate--start flex--preStart').addClass('flex--active');
      $('.animate--end').addClass('animate--start').removeClass('animate--end flex--active');
    }, 800);
  }
});

Буду очень благодарен за вашу помощь