* Move close icon to components

* Remove redundant float from close

Replace snippets and examples in dropdown docs to use semantic `ul` and `li` elements.

It results in bigger files.

Previously deprecated in v4.x, this clears out the now unused Sass option and removes some unused mixins. Arguably we could remove more, but I like the hover-focus mixin and we make extensive use of it across the project.

* Documentation tweaks

* Remove redundant col-12 classes

30 Categories , 2100+ SVG and icons from icofont

* Migration docs page for v5

* Add JS section, tweak some copy

* Update migration.md

This reverts commit 089e3334.

This reverts commit 1da5b9f7.

- Deletes mixin mentions from float docs
- Deletes mixin mention from visibility docs
- Deletes the image-replacement page for text-hide

- Drop hover and focus states
- Drop .badge-* variants and associated mixin for .bg-* utilities
- Drop .badge-pill for .rounded-pill utliity and adjust horizontal padding to find middle ground of .badge and old .badge-pill
- Remove unused variables
- Add default color value to .badge base class
- Update docs to reflect changes

This allows for the build to fail if a reference isn't found.

This happens because we have the section kind enabled (needed for examples).

This causes `p` tags which is invalid HTML.

No more Ruby dependency and most important more than 10 times less build time (at least on Windows)!