Support 'repo', 'repos' and 'parentrepo' as search operators

The new search operators are synonyms for the existing 'repository',
'repositories' and 'parentrepository' search operators.

Supporting 'repo' in addition to 'repository' makes sense since the term
'repo' is also used in the UI.

Bug: Issue 9775
Change-Id: I9b8bef425c55eb7c5d452c5a43fb4a6dbd9c7251
Signed-off-by: Edwin Kempin <ekempin@google.com>
diff --git a/Documentation/user-search.txt b/Documentation/user-search.txt
index 41cb380..7c904f5 100644
--- a/Documentation/user-search.txt
+++ b/Documentation/user-search.txt
@@ -166,7 +166,7 @@
 'PROJECT'.
 
 [[repository]]
-repository:'REPOSITORY'::
+repository:'REPOSITORY', repo:'REPOSITORY'::
 +
 Changes occurring in 'REPOSITORY'. If 'REPOSITORY' starts with `^` it
 matches repository names by regular expression.  The
@@ -174,12 +174,12 @@
 library] is used for evaluation of such patterns.
 
 [[repositories]]
-repositories:'PREFIX'::
+repositories:'PREFIX', repos:'PREFIX'::
 +
 Changes occurring in repositories starting with 'PREFIX'.
 
 [[parentrepository]]
-parentrepository:'REPOSITORY'::
+parentrepository:'REPOSITORY', parentrepo:'REPOSITORY'::
 +
 Changes occurring in 'REPOSITORY' or in one of the child repositories of
 'REPOSITORY'.