Co-Authored-By: Shohei Yoshida <fellows3@gmail.com>

Co-Authored-By: Shohei Yoshida <fellows3@gmail.com>

* Remove unused classes/styles and use utilities instead of specific styles
* Use `getElementById` instead of `querySelector`

- Add same advice about keyboard/AT handling to popovers as a callout; also add information about not adding excessive content or interactive controls (and the suggestion to opt for a modal)
- Tweak the tooltips callout for consistency

Notably:

* bundlesize 0.15.3 → ^0.17.2
* eslint-plugin-unicorn ^8.0.2 → ^9.0.0
* terser ^3.17.0 → ^4.0.0

Co-Authored-By: Martijn Cuppens <martijn.cuppens@gmail.com>

Co-Authored-By: Mark Otto <otto@github.com>

Pass the `--no-langdetect` flag instead of ignoring the warning manually.

* Prevent .sr-only-focusable overriding properties when being focused

* Typo

https://getbootstrap.com/docs/4.3/extend/approach/#z-index-scales

I think it makes more sense to link to the Bootstrap package on Yarn here (like the package link for NPM above)

This should reduce its output.