Added changeChannel support.

https://github.com/Shopify/dashing/pull/164 included support for
application-wide events, including an example event for "changing the
channel", which is exactly the functionality we require.

There are no tests for this code!
Added changeChannel support.

https://github.com/Shopify/dashing/pull/164 included support for
application-wide events, including an example event for "changing the
channel", which is exactly the functionality we require.

There are no tests for this code!
Merge branch 'feature/15441' of github.com:osuosl/fenestra into feature/15441
Initial commit of API documentation.

Added documentation for the API command 'changeChannel' which was
added as part of this feature.
Merge branch 'feature/15441' into develop