- Enable RFS
- Add documentation
- Disable doc font size overrides

This is a follow-up to #29322, specifically "allowing easy placement of
the `.form-check-input` in more places."  In my testing in Firefox and
Chrome, setting `vertical-align: top` removes the need to add
`float-left` to vertically align the checkbox and label text.  And doing
so does not visually affect examples which do apply `float: left` via
nesting in a `.form-check`.

Fix typo

* v5: Simplify navbars by requiring containers

* Update migration docs for navbar

Use our example shortcode's `class` parameter instead.

* Remove mention of icons from migration since they're not part of the core project

* Cleanup icons page to mention Bootstrap Icons

* Add variables for shades and tints of each major color

* getting-started/theming.md: use a `range`.

Add optional `$color` argument to `button-variant()` and
`button-outline-variant()` for additional flexibility.

* Scope .form-check-input layout to the .form-check parent

* Remove margin-bottom from list-group-items in case they are label elements

* document .form-check in input groups and list groups, and cleanup the no-label examples in the main .form-check docs

Stack in cards in one column when < md

Now there's only one command needed to run the docs: `npm run docs-serve`.

Also, simplify the npm scripts.

- Simplify display headings example markup
- Simplify footer styles
- Remove z-indices hacks in the docs
- Remove redundant modal styling in docs
- Use `escape-svg()` to escape docs sidebar chevron
- Simplify sidebar chevron code
- Cleanup masthead css & fix column width between `md` & `lg`
- Easier to download logo's with the `download` attribute.
- Changed some color codes into variables
- Cleanup brands css

* remove load event
* use `forEach` and `querySelectorAll`
* simplify check

- Rename and move the variable to variables file
- Move code to the grid file
- Use the mixin to generate our own classes
- Wrap in a grid classes enabled conditional
- Document the mixin