Update Button block wording

[samikeijonen]

Description

• Update button block description to mention it's a link.
• Add keyword link.

Closes #13923.

How has this been tested?

Tested on local, I see the wording change. And I can also search using keyword link.

Screenshots

Button description:

Search by keyword link:

Types of changes

• Button block description wording.
• Add keyword.

Checklist:

• [ x] My code is tested.
• [x ] My code follows the WordPress code style.
• [ x] My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.

[gziolo]

Code wise, it looks good. I would prefer to wait until someone will confirm that it is indeed the change for the description that it's expected before we proceed with merge.

[michelleweber]

A separate small thing that needs updated -- it should be "button-style." Without the dash it's a confusing phrase, and "button-style" is a bit clearer than "styled" (even though "styled" is entirely accurate).

[gziolo]

"button-style" it is 👍

[gziolo]

@samikeijonen thanks for your another contribution 🎉

[samikeijonen]

Thanks @michelleweber and @gziolo!