Merge topic 'help-command-anon-hyperlink'

119b2e62f8 cmRST: match anonymous hyperlink syntax
9ed206876f testRST: add test cases for anonymous hyperlinks

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !12482