hof/gen: document best practices for generating dependency management files like go.mod or package.json

[verdverm]

Right now, this is probably

1. run go mod tidy or similar to produce the file locally (in an example)
2. copy the file to the statics directory
   This avoids the pain of generating it

Though there may be some benefit to capturing the important versions in a CUE file?

Really this is up to the author