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/update-pkgs.sh

@@ -11,7 +11,7 @@ fi
 version="$1"
 printf "\x1b[34mINF: Using '%s' version\x1b[0m\n" "$version"
 
-for pkg in "$MYDIR"/lidm{,-bin}/; do
+for pkg in "$MYDIR"/lidm{,-bin,-systemd,-dinit}/; do
     cd "$pkg"
     printf "\x1b[1mEntering '%s'\x1b[0m\n" "$pkg"
     sed -i "s/pkgver=.*/pkgver=$1/" PKGBUILD