hints: generalize auto-follow for any unique match

fixes #1809

qutebrowser/browser/hints.py

@@ -822,6 +822,7 @@ class HintManager(QObject):
                         self._hide_elem(elem.label)
             except webelem.Error:
                 pass
+        self._handle_auto_follow()
 
     def filter_hints(self, filterstr):
         """Filter displayed hints according to a text.

qutebrowser/config/configdata.py

@@ -928,8 +928,9 @@ def data(readonly=False):
 
             ('auto-follow',
              SettingValue(typ.Bool(), 'true'),
-             "Follow a hint immediately when the hint text is completely "
-             "matched."),
+             "Follow a hint immediately when there is a unique match on the "
+             "hint text (in letter and word modes) or in the hint filter "
+             "(in number mode)."),
 
             ('auto-follow-timeout',
              SettingValue(typ.Int(), '0'),