HTML Filter for auto_linking urls in HTML.

Context options:

  :autolink  - boolean whether to autolink urls
  :link_attr - HTML attributes for the link that will be generated
  :skip_tags - HTML tags inside which autolinking will be skipped.
               See Rinku.skip_tags
  :flags     - additional Rinku flags. See https://github.com/vmg/rinku

This filter does not write additional information to the context.