Export builtin templates

[baahrens]

Hi Steven,

brilliant plugin, thank you so much!

Just wanted to ask: Would you be open to a PR that adds a overseer.builtin (or similar) export to the plugin, so that one can adjust the builtin templates before using them in setup? That would make it possible to e.g. adjust the name of the builtin templates or enforce a specific package manager for npm scripts.

[stevearc]

If you need to make adjustments to the built-in templates, you could do this a couple ways:

1. require them yourself and monkey patch in whatever changes you want
2. copy them to your own config under a new path and make your changes there. Then pass in an explicit list to templates, replacing the built-in with the path to your module.