Create playground.yml

[jdevalk]

No description provided.

[johnbillion]

Action points for me:

• Split up the build workflow in plugin-infrastructure so it can be used to build the plugin without also creating and pushing a tag
• Confirm that everything that needs to be a composite action is one

[seebeen]

@johnbillion If you want to split the build and deploy, @semantic-release/wordpress has you covered :)