Show Meetup details and esp gallery

[Fh-Ndiritu]

This adds:

1. A local meetup page for each chapter
2. Each meetup contains the date of the meetup, venue, speaker, description.
3. It has a gallery section showing all the pictures from the event. We mostly share via WhatsApp or Gphotos.
4. Could include link to blog post and YouTube Video
5. Contains reviews/comments from members

Technical details:

1. local meetup belongs to chapter
2. Gallery can use existing plugin (e.g masonrygrid)
3. Gallery is polymorphic ( can belong to meetup, chapter, conference)