Moves all gathering kinds to the form.

Can't be in the model anymore.
Updates example env file
Adds some more info to the README
Changes README format to markdown
Disables login requirement for gatherings#show
Add Friendly Id to gatherings
Fix scope with date inside. Close #10
Merge branch 'friendly_id_and_fixes' of github.com:ys/brug into ys-friendly_id_and_fixes

Conflicts:
	.env.example
	app/models/gathering.rb
Made test for future scope pass
Added URL field to gatherings (closes #11)
Merge pull request #13 from xavier/master

Added URL to gathering
Extracted list of gathering kinds into a model
Added a CSS class to event container based on the gathering kind
Display gathering kind SVG icons
Added a test for the pending inclusion of a PNG as SVG fallback
Remove saving of all Gathering records in a migration.

This would break migrations for all new developers on the project.
Fix markup and css for contact section
Adds a title for events section and a link for a new event
Remove contact and add event from navigation
Adds profile page