`0.0.0.0` has issues on Windows.

diff credits: @client9

* Tweak the accessibility/reduced motion text

include mention of carousel slides, remove the (now inaccurate, as Firefox 63 includes it too) mention that support is limited to Safari/macOS

xref https://github.com/twbs/bootstrap/issues/27525

* Add new callout for reduced motion

* Add variable to control prefers-reduced-motion media query support

* Add callout about prefers-reduced-motion to all components currently using animation which are affected

Having variables initialised from start `_isTransitioning` is better.
Would be better to add an eslint rule to check for undeclared variables use.
Reordered enter checks for `show` and `hide` by priority.

Only run `coveralls` and `check-broken-links` tasks when we run the Test phase.

I'm using Tab.js with remove function and get an error "TypeError: container is undefined [more info]", with this check the error is fixed.

- Remove `.sr-only` span for previous/next page, there is already`aria-label`
- Add `aria-disabled="true"` and `aria-current="page"`

This allows the user to make a container (ideally) to use viewport height and width and allow better vertical/horizontal alignments of elements.

Fixes #25870