✨ feat: add 2 interactive image shortcodes

- `image_hover` changes image on mouse hover.

- `image_toggler` swaps image on click.

sass/main.scss

@@ -30,6 +30,8 @@
 @import 'parts/header-anchor.scss';
 @import 'parts/header.scss';
 @import 'parts/home-banner.scss';
+@import 'parts/image-toggler.scss';
+@import 'parts/image-hover.scss';
 @import 'parts/image.scss';
 @import 'parts/misc.scss';
 @import 'parts/multilingual_quote.scss';