Add custom rules for Go

I’d like to request that Go be added to the list of languages that support custom rules:

Hello @rayharris,

As you might guess, supporting custom rules for a plugin is more than simply adding it to the list, and I don’t think we plan to support them in the near future.

In any case, thanks for the proposition, this will help to keep track of the interest for the feature, and evaluate the priority.

In the meantime, if you have ideas for new rules that could benefits for others, you can describe them and propose them in this forum, we will be grateful and happy to take them into consideration.