- Use `useradd` features to simplify user creation:
  - `-U` creates a user group,
  - `-G docker` adds the user to the `docker` group
- Document available versions and their usage
- Use `chmod 0600` before editing the file!
- Use `cat` instead of multiple `echo`es
- Comment all lines in `.env`
- Use `${FUNKWHALE_VERSION}` where applicable instead of `|version|` to
enable copy-pasting more commands