bat 0.20.0

A cat(1) clone with wings.
Documentation
# Release checklist

## Version bump

- [ ] Update version in `Cargo.toml`. Run `cargo build` to update `Cargo.lock`.
      Make sure to `git add` the `Cargo.lock` changes as well.
- [ ] Find the current min. supported Rust version by running
      `grep '^\s*MIN_SUPPORTED_RUST_VERSION' .github/workflows/CICD.yml`.
- [ ] Update the version and the min. supported Rust version in `README.md` and
      `doc/README-*.md`. Check with `git grep -i 'rust.*1\.'` and
      `git grep -i '1\..*rust'`.
- [ ] Update `CHANGELOG.md`. Introduce a section for the new release.

## Update syntaxes and themes (build assets)

- [ ] Install the latest master version (`cargo clean && cargo install -f --path .`) and make
      sure that it is available on the `PATH` (`bat --version` should show the
      new version).
- [ ] Run `assets/create.sh` and check in the binary asset files.

## Documentation

- [ ] Review the `-h` and `--help` texts
- [ ] Review the `man` page (`man $(fd -HIp target/release/build.*out/assets/manual/bat.1) | tee`)

## Pre-release checks

- [ ] Push all changes and wait for CI to succeed (before continuing with the
      next section).
- [ ] Optional: manually test the new features and command-line options. To do
      this, install the latest `bat` version again (to include the new syntaxes
      and themes).
- [ ] Run `cargo publish --dry-run --allow-dirty` to make sure that it will
      succeed later (after creating the GitHub release).

## Release

- [ ] Create a tag and push it: `git tag vX.Y.Z; git push origin tag vX.Y.Z`.
      This will trigger the deployment via GitHub Actions.
- [ ] Go to https://github.com/sharkdp/bat/releases/new to create the new
      release. Select the new tag and also use it as the release title. For the
      release notes, copy the corresponding section from `CHANGELOG.md` and
      possibly add additional remarks for package maintainers.
      Publish the release.
- [ ] Check if the binary deployment works (archives and Debian packages should
      appear when the CI run for the Git tag has finished).
- [ ] Publish to crates.io by running `cargo publish` in a *clean* repository.
      The safest way to do this is to clone a fresh copy.

## Post-release

- [ ] Prepare a new (empty) "unreleased" section at the top of `CHANGELOG.md`.