Add staggered term limits to CWG

For context on past membership and historical group turnover, the CWG currently consists of:

• One member who joined the CWG in March 2013, and has served as chair since March, 2016.
• One member who joined in August 2014.
• One member who joined in December 2015.
• One member who joined in April 2016.
• Two members who joined in May 2017.

Past members include:

• One member who joined the CWG in March 2013 and stepped down in August 2014.
• One member who joined the CWG in March 2013 and stepped down in October 2015.
• One member who joined the CWG in March 2013 and stepped down in March, 2016, but continued to serve the CWG in an ex officio capacity until May 2017

Many nonprofits (including the Drupal Association) limit service to two 3-year terms, or 6 years total. I think something like this could work for the CWG, particularly if the terms were staggered so that 1-2 members rotated every year or two. I'd also suggest that only members in their second term were eligible for leadership positions in the group (e.g, chair).

As this would require changes to our charter, I agree that this is probably most appropriate to bring up in the context of larger community governance discussions.

As this would require changes to our charter, I'm marking it Postponed pending further governance discussions.

Updating this issue as we now have a concrete proposal for changes to the CWG charter that would include adding term limits: #3011215: Proposed Changes to the Community Working Group Charter

Closing this issue, as we have adopted a new charter specifying that "a member may serve up to two 3-year terms (6 years total)."