feat: initial PKGBUILD collection for the Moonarch ecosystem

Add PKGBUILDs for moonset-git, moonlock-git, and moongreet-git.
Intended as a paru custom AUR source for easy installation of
all Moonarch components via `paru -S moonset-git`.

moongreet-git/.SRCINFO

@@ -0,0 +1,19 @@
+pkgbase = moongreet-git
+	pkgdesc = A greetd greeter for Wayland with GTK4 and Layer Shell
+	pkgver = 0.3.1.r5.g4c9b436
+	pkgrel = 1
+	url = https://gitea.moonarch.de/nevaforget/greetd-moongreet
+	install = moongreet.install
+	arch = x86_64
+	license = MIT
+	makedepends = git
+	makedepends = cargo
+	depends = gtk4
+	depends = gtk4-layer-shell
+	depends = greetd
+	provides = moongreet
+	conflicts = moongreet
+	source = git+https://gitea.moonarch.de/nevaforget/greetd-moongreet.git
+	sha256sums = SKIP
+
+pkgname = moongreet-git