Initial draft for capturing internal go standards

As someone that wishes to see greater go adoption within GDS
I would like to have something to point people at
So that they feel welcome and confident when proposing changes
Add channel section

The one thing that I have a strong opinion on at this point.
Add another dependency-management option
Extend Go styleguide
Add readme link to Go styleguide
Fix typos in the Go styleguide
Merge pull request #57 from alphagov/golang

Add Golang guidance