init(), после this.setup() дописываем this.showFirstLastLetter()showFirstLastLetter()showFirstLastLetter: function(){
this.guessLetterInput.val(this.wrd.letters[0].letter);
this.guessForm.trigger('submit');
this.guessLetterInput.val(this.wrd.letters[this.wrd.totalLetters-1].letter);
this.guessForm.trigger('submit');
},