Add link to edit an Ignite community.
Add link to edit an Ignite community.

https://github.com/madewithbytes/us_ignite/issues/97

Only the ``guardian`` of a community will be able to see and
edit the ``Hub``.

The edit form can be accessed from the detail page of
a community.

us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite