As of release 13.1, we have added support for a command repository. This was hinted at earlier in this post. Please check out the following links for documentation and tips on usage.
Offcial product documentation
Public github repo of commands (contributions accepted)
And you thought Go didn't support Maven, Nuget or Chef?
Use Go's new command repository to lookup your config scripts (advanced)
Somewhat related reading:
Understanding Go's custom command
One task per job