className="myFavoriteClass" => className="my-favorite-class"
sed -e "s/className=\"\([A-Z]\)\"/className=\"\L\1\"/g" "src/components/$1"/"$2.jsx"
sed -e "s/\([A-Z]\)/-\L\1/g" "src/components/$1"/"$2.jsx"
sed -r '
s/(className="[^"]+)([A-Z])([^"]+)([A-Z])([^"]+)([A-Z])([^"]+")/\1-\L\2\3-\L\4\5-\L\6\7/g;
s/(className="[^"]+)([A-Z])([^"]+)([A-Z])([^"]+")/\1-\L\2\3-\L\4\5/g;
s/(className="[^"]+)([A-Z])([^"]+")/\1-\L\2\3/g
' input_file > output_file
sed -i -r '
s/(className="[^"]+)([A-Z])([^"]+)([A-Z])([^"]+)([A-Z])([^"]+")/\1-\L\2\3-\L\4\5-\L\6\7/g;
s/(className="[^"]+)([A-Z])([^"]+)([A-Z])([^"]+")/\1-\L\2\3-\L\4\5/g;
s/(className="[^"]+)([A-Z])([^"]+")/\1-\L\2\3/g
' *.jsx