Add doc comment to moveHEADToCommit:error:

Author: phatblat

ObjectiveGit/GTRepository.h

@@ -269,12 +269,20 @@ extern NSString * const GTRepositoryInitOptionsOriginURLString;
 /// Returns a GTReference or nil if an error occurs.
 - (nullable GTReference *)headReferenceWithError:(NSError **)error;
 
-/// Move HEAD reference safely, since deleting and recreating HEAD is always wrong
+/// Move HEAD reference safely, since deleting and recreating HEAD is always wrong.
 ///
+/// reference - The new target reference for HEAD.
 /// error - If not NULL, set to any error that occurs.
 ///
 /// Returns NO if an error occurs.
 - (BOOL)moveHEADToReference:(GTReference *)reference error:(NSError **)error;
+
+/// Move HEAD reference safely, since deleting and recreating HEAD is always wrong.
+///
+/// commit - The commit which HEAD should point to.
+/// error - If not NULL, set to any error that occurs.
+///
+/// Returns NO if an error occurs.
 - (BOOL)moveHEADToCommit:(GTCommit *)commit error:(NSError **)error;
 
 /// Get the local branches.