Help: Add missing external link marker.
Help: Document that file(GENERATE) re-writes only when needed.
Help: Add comma to assist parsing of ctest_build command docs.
Merge topic 'minor-help-cleanup' into next

7eef823e Help: Add comma to assist parsing of ctest_build command docs.
5fb9b16d Help: Document that file(GENERATE) re-writes only when needed.
95135ac3 Help: Add missing external link marker.