Add source package tag doc

doc/manual/tags.md

@@ -495,16 +495,49 @@ Transfiletrigger-tags run once per transaction.
 
 ## Source packages
 * Buildarchs (1089) string array
+
+  If present, specifies the architectures the package may be built for.
+
 * Excludearch (1059) string array
+
+  If present, limits the architectures on which the package is buildable
+  by excluding those specified.
+
 * Excludeos (1060) string array
+
+  If present, limits the operating systems on which the package is buildable
+  by excluding those specified.
+
 * Exclusivearch (1061) string array
+
+  If present, limits the architectures on which the package is buildable
+  exclusively to those specified.
+
 * Exclusiveos (1062) string array
+
+  If present, limits the operating systems on which the package is buildable
+  exclusively to those specified.
+
 * Nopatch (1052) int32 array
+
+  Denotes a patch number for which source is not supplied.
+
 * Nosource (1051) int32 array
+
+  Denotes a source number for which source is not supplied.
+
 * Patch (1019) string array
+
+  Patch file names.
+
 * Source (1018) string array
+
+  Source file names.
+
 * Sourcepackage (1106) int32
 
+  Denotes a source rpm.
+
 ## Internal / special
 * Headeri18ntable (100) string array
 * Headerimmutable (63) bin