Fix #17234

update broken holder.min.js link

Fix #17175

X-Ref Original Against Wrong Branch: #17179

Calls out the new `.table-inverse`, `.table-reflow`, `.thead-default` and `.thead-inverse`

Audit the new table variants in V4 that aren't in V3

Fix #17177

Simplest example is using horizontal variants using rows.

Fix #17182

Otherwise the "Heads up!" is at the end of the previous line, making the connection to the warning unclear.

[skip sauce]

Mostly links.
Fixes #17056.

Fixes #17096

Example:
> ... SCSS variables (e.g., `@enable-gradients: true`) ...
Referenced SCSS but used the LESS syntax. Changed to:
> ... SCSS variables (e.g., `$enable-gradients: true`) ...

Closes #17114