Create a block that can be used for the block editor (Gutenberg)

[rumspeed]

The metabox works as is in WP 5.0. It is a little hard to find but it works. The native "Button" block works pretty well. We may not need to continue support for this plugin. If we do...

We could create a new block called CTA. That would work similar to the button block, but pull in the background color and style the button dynamically.