There's no reason for us to wait here.

Some of the snippets need to be updated later.

* Prep for v4.3.0

* More updates for v4.3.0.

* rerun to build docs source map

- 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

This reverts commit b04f97f6.

This allows us to generate the anchor links on build time.

https://github.com/allejo/jekyll-anchor-headings

(again)

https://github.com/twbs/bootlint/wiki/W007

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.

Also, move the search code to a separate file.

Rely on `site.url` which is different for production. In that case do nothing with the search result, otherwise when in development remove our url from it.

Previously a search redirected to `https://getbootstrap.com/...`

* Update copyright range to include 2018

* Extend copyright date range on new files from 2017 to include 2018

This makes them keyboard-accessible. For mouse users, the only change
here is that the focus outline will remain on the button once clicked
(in future, this can be solved with :focus-ring, but for now this would
require a polyfill). the tooltip is explicitly hidden on `mouseleave`,
so even though the `<button>` retains focus after clicking, the tooltip
won't stay visible once mouse user moves away.
the mouse hover styles have explicitly not been make to also apply to
:focus, so as to minimise the visual impact for
mouse users (though the tooltip remains visible)
 - but due to the default outline and the custom tooltip, it
should be fairly clear when keyboard users set focus to a copy button
too.

* Fixed incorrect instruction: "Press ⌘ to copy"

It needed to be "Press ⌘C to copy"

* Updated to concatenate copy string

Updated copy command to concatenated string to prevent potential issues

* Updated the way the copy string concatenates

As per excellent suggestion by @tomlutzenberger

* Removed semicolon line endings

;P

* var not const or let