Add `src actions create` command to create actions.json boilerplate

Created by: ryan-blunden

To help surface the actions schema and show different step examples, create a create-schema command which would create an action.json file in the current directory. I'd advise skipping the dumping it to stdout so the user can successfully do it the first time around without re-executing it with redirection to a file.

In the boilerplate file, a $schema field would be added to surface the schema.

This would make tutorial videos and instructions for creating an initial action.json file super easy and preconfiguring support for code completion and code doc hovers in VS Code would be really cool.