Playground Block: Simplify running Core and Gutenberg PRs

[dmsnell]

It would be great if inside the Playground Block one could have an auto-completer search Gutenberg and Core PRs to apply to the Playground.

As often as I share a Playground Block, I'm usually doing it for development purposes to show how code in a patch, or a combined patch between the two repos, can be written and possible.

This currently requires creating Blueprint steps, remembering to run through a Github proxy, remembering to use the right domain (since CORS issues relate to the blog on which the block appears, no longer to playground.wordpress.net), and remember how to merge that with any other potential Blueprints.

If we had a selector in the Block Controls that could automatically fill in these details and merge them with whatever Blueprints are chosen, it would make it that much easier to demonstrate test setups. It would also make it more convenient to try out different sets of Blueprints with various Core and Gutenberg patches running, whereas we wouldn't have to edit every single one of those Blueprints.

[adamziel]

Boot protocol will greatly simplify loading WordPress core PRs, and from there this fill be about UX improvements in the block.

[dmsnell]

this fill be about UX improvements in the block.

This issue specifically is all about the UX of the block, however it happens technically.