Add `class` to toolbar buttons

[jonyhayama]

I'm submitting a...

• Bug report
• Feature request

Request

Add class with button names to toolbar buttons.

Current version is:

<div class="editor-toolbar">
  <button title="Bold (Ctrl-B)" tabindex="-1"><i class="fa fa-bold"></i></button>
  ...
</div>

I'd like to propose we simply add a class, like this:

<div class="editor-toolbar">
  <button title="Bold (Ctrl-B)" class="editor-button-bold" tabindex="-1"><i class="fa fa-bold"></i></button>
  ...
</div>

This would allow CSS styles to be applied on a single button, eg. A save button shown in a different color when it detects changes that nees to be saved.

I'm more than happy to submit a Pull Request, I'm opening this issue just to check if it is OK to do so :)

[CWharton]

I would gladly welcome a PR