see #22944 and #24620

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.

Fixes #26830

Only bundlesize is kept back for Node.js 10.x compatibility.

Fixed logo in README

* OS X is now macOS

* Update browser-bugs.yml

The 'Floating labels' example is only supported on Chrome, Safari and Firefox. On Edge and IE the label is displayed always and any text input overlaps the label which makes it unreadable.

The fix here targets Edge and IE and makes the form behave normally, the labels are hidden and the placeholder color is standard.

- Fixes #25656 where custom selects had the wrong focus shadow
- Fixes #26668 where custom selects had no inset shadow (also closes #26572 which had the wrong form classes on the first example anyway)

`disabled` class is not needed for wrapper.

I was getting port in use errors.

Newer bundlesize versions still don't work with node.js 10.x.

babel has some bugs that we need to be fixed.

Add additional wording to the Introduction section of Bootstrap docs about the bootstrap bundle js (#26688)

saves a redirect