update example configurations and schema

src/modules/packages/packages.conf

@@ -11,6 +11,7 @@
 #  - urpmi       - Mandriva package manager
 #  - yum         - Yum RPM frontend
 #  - zypp        - Zypp RPM frontend
+#  - pamac       - Manjaro package manager
 #
 # Not actually a package manager, but suitable for testing:
 #  - dummy       - Dummy manager, only logs

src/modules/packages/packages.schema.yaml

@@ -17,6 +17,7 @@ properties:
             - urpmi
             - yum
             - zypp
+            - pamac
             - dummy
 
     update_db: { type: boolean, default: true }