help: tweak keyword format output

mercurial/commands.py

@@ -3369,8 +3369,8 b' def help_(ui, name=None, unknowncmd=Fals'
                          ('extensions', _('Extensions')),
                          ('extensioncommands', _('Extension Commands'))):
             if matches[t]:
-                ui.write('%s:\n' % title)
-                ui.write(minirst.format(minirst.maketable(matches[t])))
+                ui.write('%s:\n\n' % title)
+                ui.write(minirst.format(minirst.maketable(matches[t], 1)))
         return
 
     if name and name != 'shortlist':