docs: document main package

cmd/abra/main.go

@@ -1,10 +1,14 @@
+// Package main provides the command-line entrypoint.
 package main
 
 import (
 	"coopcloud.tech/abra/cli"
 )
 
+// Version is the current version of abra.
 var Version string
+
+// Commit is the current commit of abra.
 var Commit string
 
 func main() {
@@ -17,5 +21,4 @@ func main() {
 	}
 
 	cli.RunApp(Version, Commit)
-
 }