Create release manager schedule

[elycheea]

Thanks to @annawen1’s documentation on releases, it’s probably time us to share the responsibilities.

A few ways we can document our schedule, e.g. Box note or wiki, but mostly we want to ensure where we log this is somewhere we can easily track.

### Tasks
- [x] Decide as a team where to keep schedule
- [ ] Create the rotation based on schedule with lead and support roles
- [ ] Add to slack

[matthewgallo]

https://github.com/carbon-design-system/carbon/wiki/Release-rotation possible option of using wiki similar to core. dotcom is using a boxnote which is another option as well

[kingtraceyj]

We will keep rotation in wiki