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

* Prep for v4.3.0

* More updates for v4.3.0.

* rerun to build docs source map

Mostly be consistent with the attributes' order and improve compression when possible.

They don't use it.

- Move 4.1 docs to 4.2
- Update versions everywhere to 4.1.3 with release script
- Manually bump the shorthand version in package.json
- Add 4.2 to the versions docs page
- Update some redirects
- Fix tests asset URLs
- Bump Nuget and more

* SVG accessibility fixes

- add `focusable="false"` to all SVGs, to stop IE from including the `<svg>` in its default focus cycle
- completely hide decorative SVGs using `aria-hidden="true"`
- add `role="img"` to meaningful/"content" SVGs, ensure they have an appropriate `<title>` and/or `aria-label`
- simplify placeholder default title

* Simplify usage of placeholder.svg in the docs

- in most cases, no need for separate/redundant text and title (now that we make text itself part of the alternative text explicitly)
- no need (expect in rare cirumstances) to describe the placeholder image (unless the look of the image is important/the actual content, as is the case with the image thumbnail class)

* Simplify example.html rewriting of <svg> to <img> code sample

- as the `alt` for the placeholder isn't really important, just add an ellipsis instead (otherwise, to be correct, we'd have to construct the whole "title+text" construct like we do now in the
placeholder.svg itself

* Change svgo configuration to retain role attribute and add/force focusable=false

- regarding `focusable=false`, see https://github.com/svg/svgo/issues/1011 (which would be the "proper" SVGO fix) and the (hacky) solution https://github.com/svg/svgo/pull/817

For Markdown files, this isn't needed because the Markdown converter takes care of this.

Reduces duplication and makes maintenance easier.

With the current docs directory setup, I'm making too many mistakes and have to manually address path changes and directory moves on deploy. This makes for a frustrating experience developing locally and shipping releases. With this PR, we're basically back to the same setup from v3—duplicating the dist directory into our docs directory. Not the most ideal, but very straightforward for me as the release manager.

* update docs path from docs/4.0/ to docs/4.1/

* bump version to 4.1.0

* Update redirects to work for 4.1 docs move

* Update docs version switcher to include latest and link to 4.0 docs

* re-run dist

* Update package-lock.json

* Update docs-navbar.html

* fix cover nav

* Improve signin visuals and alignment with that flexbox love

* rewrite cover example in flexbox

* lighten signin bg

* first pass at pricing example

* redo examples index with data file

* tighten up spacing a bit

* update navbar descriptions

* link pricing

* move that back

* property order

* Fix test errors.

* Compress pricing.png.

* add form validation example

* remove that

* rename that

* restyle and space out

* fix errors

* change order

* cleanup album css and styles

* tweak examples index

* make it a badge

* options

* improve sticky footer alignment

* redesign example index

* brand new blog layout

* start new screenshots

* new product example page a la apple

* add email field

* fix linter, remove unused blog css

* hook up feather icons to start

* redo dashboard

* fix linting

* add floating labels example

* formatting

* formatting

* lint

* fix values on select

* optional input, plus input group

* new dashboard image

* start to reboot the offcanvas example

* updated images

* new offcanvas mostly implemented

* linting

* edit description

* more description changes

* - Add vertical margin to album hero buttons for when they're stacked
- Adjust font-size and padding for pricing header and hero
- Fix checkout's stacked column margins, plus update their check/radio
markup
- Update product's utilities to be responsive
- Made blog cards somewhat responsive (needs a bit more work tbh)

* drop leading zero

* more linting

* swap empty images for holder, fix border

* dist the docs

* navbars have no margin-bottom to begin

* add css var, tweak padding for mobile

* comment headers

* nix commented out code

* nix the navbar structure for a custom one, stack it on mobile

* tweak heading button group for mobile

* Removed narrow jumbotron and justified nav examples as these are easily accomplished with new components in v4

* improve card sizing on pricing

* update and compress

Having it uppercase doesn't offer anything and the lowercase version slightly improves gzip compression.

* use a trailing slash when possible
* use https when possible
* remove a few redirected links
* consistently use `https://popper.js.org/`
* fix `iconUrl` in nuget files
* change Jekyll Windows guide to the official one

Structure examples with appropriate `<main>`, `<header>`, `<footer>`

Bootstrap 4.0 Beta 1 dropped the offset classes in favor of using margin utilities. Update the blog example in the docs to use the appropriate `ml-auto` instead of `offset-sm-1` class to retain a pixel perfect with previous versions.

fix location of favicons so it loads when viewing the examples. This is the only one I found in the project, so I am assuming it is the right one to point to (#22895)