Ignore CI generated docs

Author: firthm01

.gitignore

@@ -19,4 +19,8 @@ submodules/VST3
 packaging/codesign/*.dmg
 packaging/codesign/*.tar
 packaging/codesign/*.zip
-packaging/codesign/tmp
+packaging/codesign/tmp
+# These docs are generated by CI. Not ignoring will cause -dirty flag on version labels.
+packaging/README.md
+packaging/README.pdf
+packaging/LICENSE.pdf