Hey, I just made a Pull Request!
Added a new Scaffolder Backend Yeoman module to allow for integration with Yeoman Generators. At the moment the only action added is 'run' to execute installed Yeoman Generator.
The Yeoman Generator can be either added as a dependency in package.json of a service that uses this plugin or installed in an environment using npm install -g https://github.com/org/generator-name.git
Tests for yeomanRun.ts were not added because 'yeoman'environment' module is exported in a way that does not allow partial mocking while '@types/yeoman-environment' does not support Yeoman 3.x, yet.
I also tested it E2E.
I did not add changeset since this is an initial commit for this module. Let me know if changeset is needed.