Index hashtags, and ... mentions.  Also allow the user to specify that the tweet text to be markedup.

The backend code for https://github.com/walkeriniraq/twitarr/issues/125

This adds:
GET http://localhost:3000/api/v2/stream/m/:username
and
GET http://localhost:3000/api/v2/stream/h/:hash_tag

Also allows the URL param for the stream: &auto_link=true
Which will markup the text of the post.

When enabled, you can also specify these options to customize the linking:
:list_class, :username_class, :hashtag_class, :cashtag_class, :username_url_base, :list_url_base, :hashtag_url_base, :cashtag_url_base, :invisible_tag_attrs

See https://github.com/twitter/twitter-text-rb/blob/master/lib/twitter-text/autolink.rb#L11 for a description of what each one does.