Terms and Term Limits for Chairs

Following up from Steering Committee meeting July 12th, we are going to split issue #5855 into three parts:
1- the original issue #5855: mechanism for selection,
2- defining terms and any limits associated (this issue),
3- should 1 tech lead be a required role for each SIG in addition to 1 chair (sig-governance.md change)

------

Chairs should have terms and potentially limits.

Why:
1. Responsiveness of overburdened chairs #4289 who have multiple roles and "hats" within the project (several related linked issues inside of that issue that would be related)
2. No current forcing function to think about succession or do outreach for new chairs and/or tech leads
3. Will help build a leadership pipeline that feeds into multiple areas of the project including Steering
4. New people bring fresh ideas and help us find holes that helps with sustainability
5. will help with getting support from employers with defined terms and how long they will be doing a Thing
6. avoid BDFL in certain areas; try to match elected processes for other leadership like steering
7. Folks have identified problematic areas of self-selecting and former chair nominations: -no one wants to speak out on a mailing list, -no one was asked publicly which could limit diversity and other beneficial community building, -community members didn't know a chair was an opportunity for them
7. [will update]

Knowns:
- [data placeholder for how many explicit tech leads we have and combo chair/tl]
- [data placeholder for average time served and other time metrics]
- Current process lacks any kind of re-evaluation / community evaluation (annual reports touches this area)

Open Questions:
1 What's a term defined as?
2 How long should a term be?
3 Option to renew? / extend? / eligibility for same role in another part of the project?
4 should the scope of this issue be just chairs or chairs and TLs?

Proposed solution(s):
- will collect discussion themes here
- 2 year term, 4 year limit
- voting