Thank you all.
I guess.. I think this is "all a bit complicated" to learn in the time available. I may revisit later, but for now I think some feedback / an output is that it would be useful to:
- be able to install just by giving a github repository
- provide a simple / guided Manifest creator form (with some best-guess defaults)
I appreciate that these things are easier said than done, and may for all I know be entirely impossible / wrong thing to ask for.