Merge branch 'allow-abbr' into 'develop'

Allow use of the `abbr` HTML tag.

See merge request pleroma/pleroma!405

lib/pleroma/html.ex

@@ -91,6 +91,8 @@ defmodule Pleroma.HTML.Scrubber.Default do
   Meta.allow_tag_with_uri_attributes("a", ["href"], @valid_schemes)
   Meta.allow_tag_with_these_attributes("a", ["name", "title"])
 
+  Meta.allow_tag_with_these_attributes("abbr", ["title"])
+
   Meta.allow_tag_with_these_attributes("b", [])
   Meta.allow_tag_with_these_attributes("blockquote", [])
   Meta.allow_tag_with_these_attributes("br", [])