Git-machete

- added: arm64 packages in Ubuntu PPA

- fixed: reading tokens from `~/.github-token` for GitHub Enterprise domains (reported by mkondratek)
- fixed: `git machete github retarget-pr`, when invoked without `--ignore-if-missing`, actually fails now if there is no PR for the branch
- improved: GitHub tokens are automatically redacted from command outputs in `--debug` mode

- fixed: `machete.github.remote` git config key can be specified independently from `machete.github.organization` and `machete.github.repository`

- added: `git machete completion bash|fish|zsh` command
- fixed: multiple glitches in the existing bash/fish/zsh completions

- improved: layout of documentation at ReadTheDocs
- improved: replaced `definition file` with `branch layout file` across the docs

- fixed: building the package for Ubuntu PPA