Fix docutils deprecation and main_menu is_active rendering

Replace deprecated docutils.frontend.OptionParser with
get_default_settings(). Override iommi_open_tag in BoundM to
set is_active class before delegating to Tag.iommi_open_tag().

Author: boxed

iommi/docs.py

@@ -52,8 +52,7 @@ def uses_from_cookbooks():
     from iommi.declarative.util import strip_prefix
 
     parser = docutils.parsers.rst.Parser()
-    components = (docutils.parsers.rst.Parser,)
-    settings = docutils.frontend.OptionParser(components=components).get_default_values()
+    settings = docutils.frontend.get_default_settings(docutils.parsers.rst.Parser)
 
     backrefs = defaultdict(set)
 

iommi/main_menu.py

@@ -386,6 +386,11 @@ def render(self):
     def __repr__(self):
         return f'<BoundM {self.m.name}>'
 
+    def iommi_open_tag(self):
+        if self.is_active():
+            self.attrs['class']['is_active'] = True
+        return super().iommi_open_tag()
+
     def iommi_open_details_tag(self):
         return format_html('<details{}>', " open" if self.open else '')