• Move the Bootstrap SVG into the same folder

Without this, the CSS and JS files don't get copied over to the `docs/dist/` folder during development. I imagine we can simplify this and not run it twice, and instead run it once? Unsure.

/cc @johann-s

According to the docs, you just need to apply the `navbar-nav` to an
`<ul>` tag in a list-based navbar. In fact, `navbar-nav` seems to
override all the css properties set by `nav`.

Also, `nav-item` class should be used only for `<li>` tags, or in
conjunction with `<a>` tags to entirely avoid the list-based approach.

This commit removes the redundant `nav` class from `navbar-nav` `<ul>`
tags, moves `nav-item` from `<a>` tags to `<li>` tags and properly
adds `nav-item` class to `<li>` tags where missing.

Refs:

* https://v4-alpha.getbootstrap.com/components/navs/
* https://v4-alpha.getbootstrap.com/components/navbar/#nav

Rename `$navbar-*-toggler-bg` to `$navbar-*-toggler-icon-bg` since it's placed on .navbar-toggler-icon (#22564)

* add the svg icon as a partial so we can include it easily

* add the icon to the homepage

* drop .bd-booticon for svgs here

* rip out the import for .bd-booticon sass file

* Delete _booticon.scss

* indentation

* Update bootstrap-icon.html

* remove those

The premise for #22376 was that if we removed the `max-width` and `flex` properties, we could use the column classes as `width` utilities. The problem that I didn't remember at the time is that column classes have horizontal `padding` on them. This doesn't work for setting `width`. Perhaps more importantly, this causes #22649—the automatic sizing of columns is broken with the absence of `flex` styles.

/cc @sachinsinghi

* Add box-shadow to .progress-bar

Puts an unused variable back in use for when folks set `$enable-shadows` to `true`.

* add webpack to documentation"

implementing PR comments

implementing PR comments

* replace tether with popper

* Fixed dead link to browser list

The link to the list of browsers supported through Autoprefixer was dead, now updated to a working link.

* Updated label to display new file path

Changed the labeling on the updated link to show read as the new updated file path.