To make it clearer what is and isn't generated content, make gen place
all generated output in `target/gen`.
Also, try to make the readme clearer about the location of build
artifacts.
type: development
Don't commit man pages, since that bloats commits.
Attempt to build them in `bin/package`. This is fraught, since we need
`help2man`. Hopefully this works!
type: development
Committing the completion scripts bloats diffs, so stop committing them.
Before copying release files, generate the scripts in `bin/package`.
type: development
The book should eventually contain all documentation that isn't suitable
for the readme or help text.
For now it's empty, but it seemed useful to add the scaffolding, so
adding to it is low friction.
type: documentation
