markdown: note about the escape_html_text wrapper

Signed-off-by: Conrad Hoffmann <ch@bitfehler.net>

srht/markdown.py

@@ -129,6 +129,8 @@ class SrhtRenderer(m.HTMLRenderer):
         return template.format(level=level, inner=inner, _id=_id)
 
     def escape_html_text(self, value):
+        # This wrapper handles a name change introduced in mistletoe v1.1.0.
+        # It can simply be removed once backwards compatibility is no longer needed.
         sup = super()
         if hasattr(sup, 'escape_html_text'):
             return sup.escape_html_text(value)