purge: fix formatting of lists with proper reST markup

hgext/purge.py

@@ -36,10 +36,13 b' def purge(ui, repo, *dirs, **opts):'
     uncommitted changes in an otherwise-clean source tree.
 
     This means that purge will delete:
+
      - Unknown files: files marked with "?" by "hg status"
      - Empty directories: in fact Mercurial ignores directories unless they
        contain files under source control management
+
     But it will leave untouched:
+
      - Modified and unmodified tracked files
      - Ignored files (unless --all is specified)
      - New files added to the repository (with "hg add")