chore: misc (#100) (this makes 2.0.0)

Co-authored-by: grialion <48643945+grialion@users.noreply.github.com>

- Fix license ambiguity (#88)
  - just the only/or-later ambiguity point, not adding SPDX identifyiers unless more people request it
- Better document kmscon (#91)
- Make 2.0.0 already to close #86
- Add a changelog
- Add packagers info (acutally just add them to install guide)
- Add AUR service packages (I'll take care of systemd and dinit, let others package the rest and leave systemd open for someone who actually uses it in docs)
- Make sure all makefile installs to `/usr/local` by default
- Simplify Makefile complexity by several orders

assets/pkg/aur/makepkg-clean.sh

@@ -5,7 +5,7 @@ MYSELF=$(realpath "$0")
 MYDIR=$(dirname "$MYSELF")
 
 cd "$MYDIR"
-typeset -a pkgs=(lidm{,-git,-bin})
+typeset -a pkgs=(lidm{,-git,-bin,-systemd,-dinit})
 
 for pkg in "${pkgs[@]}"; do
     printf "\x1b[mEntering '%s'\x1b[0m\n" "$pkg"