add plus section for metadata

patch.yml

@@ -2,6 +2,9 @@
 # build_patch: These needed modifications to build properly or they are being
 #              addressed for other issues that isn't done upstream. These show
 #              what branch has patches applied.
+# plus: These packages are modified versions of base packages to add features
+#       not available or patched out by upstream. These are potentially packages
+#       that should be available in the main distribution but are not.
 # previous: These are previously patched packages that are no longer patched in
 #           Rocky as they are upstreamed or it was found no longer required.
 # provides: These are specific branded packages that provide something else
@@ -24,6 +27,10 @@ build_patch:
     - python-psycopg2
   r8:
     - python-cups
+
+plus:
+  all:
+    - thunderbird
 previous:
   - ipa
 provides: