message: Add FAQ entry for where to develop plugins
diff: @@ -12,3 +12,11 @@ It strikes a good balance between power, customisability, and ease of use. Since
  focus of Backstage is to make plugin developers productive with as few hurdles as
  possible, material-ui lets plugin makers both get going easily with well-known tech
  and a large flora of components.
  +
  +## Are you planning on having plugins cooked into the repo or should they be developed in separate repos?
  +
  +Additional open sourced plugins would be added to the `plugins` directory in this monorepo.
  +
  +While we encourage using the open soure model, integrators that want to experiment with
  +Backstage internally may also choose to develop closed source plugins in a manner that suits
  +them best, for example in their respective Backstage source repository.
  