Add demo functions

build/scss/_cards.scss

build/scss/_dropdown.scss

build/scss/_miscellaneous.scss

dist/css/adminlte.css

dist/css/adminlte.css.map

dist/css/adminlte.min.css

dist/js/adminlte.min.js

dist/js/adminlte.min.js.map

dist/js/demo.js

index.html

index2.html

index3.html

package-lock.json

package.json

pages/UI/buttons.html

pages/UI/general.html

pages/UI/icons.html

pages/UI/sliders.html

pages/calendar.html

pages/charts/chartjs.html