* 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
Callouts are already excluded from ToC, but due to a limitation in jekyll-toc they are still being included.
We should revisit this if the bug is fixed later.
* 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
In the event that the content is larger than the image, the content will continue to be displayed outside the image itself. There are some workarounds but they apply only to browsers that support this option and IE11 is not one of them.
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.
