How do I add a custom flight mode? (Instructions say to raise an issue?)

#### Issue details
http://ardupilot.org/dev/docs/apmcopter-adding-a-new-flight-mode.html

Basically what I'm trying to make it so that I can press a button in mission planner, and then have my drone complete a simple pre-programmed aciton (ie: flying in a certain shape).

I thought this would be a straightforward thing to add it and make it appear in mission planner, but the instruction say to raise an issue here (apparently expecting someone to do it for me?).

Is there a straightforward way I can do what I'm trying to do without having to modify mission planner?

#### Platform
[ ] All
[ ] AntennaTracker
[ X ] Copter
[ ] Plane
[ ] Rover
[ ] Sub

Read the linked custom-flight-mode instructions and the existing Mission Planner issue discussion first. Determine whether the requested Copter button and pre-programmed action are supported without modifying Mission Planner; done would require a documented, agreed implementation scope or a clear supported alternative.

Written by the indexing model from the issue text.