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/lidm-bin/.SRCINFO

@@ -1,15 +1,16 @@
 pkgbase = lidm-bin
 	pkgdesc = A fully colorful customizable TUI display manager made in C. (release binary)
 	pkgver = 1.2.3
-	pkgrel = 3
+	pkgrel = 4
 	url = https://github.com/javalsai/lidm
 	arch = x86_64
 	arch = i686
 	arch = aarch64
 	arch = armv7h
 	arch = riscv64
-	license = GPL
+	license = GPL-3.0-only
 	depends = libpam.so
+	depends = lidm-service
 	provides = lidm
 	conflicts = lidm
 	source = lidm-default-theme-1.2.3.ini::https://raw.githubusercontent.com/javalsai/lidm/v1.2.3/themes/default.ini