clarify nomination process for Technical Committee members

[bjohansebas]

Just a small rewording to make it clear that only TC members can nominate others to become TC members

Important

If this is approved by the TC, an issue must be opened in the CPC for their approval as well, since it is a change to the CHARTER

[ctcpip]

per TC discussion, blocking for now as we work through how best to deal with this

[wesleytodd]

As discussed:

1. We should handle these nominations in a consistent way across all roles
2. Nominations should be done in private, suggest reaching out in slack or email

We may need to follow up with other docs to apply this process in the right places. Those don't need to block this PR, but we need to at least reflect the private nomination in this PR.

[bjohansebas]

Also, the other reason this PR was being blocked was because we needed to decide whether to include it in the charter or in the governance file.

[ctcpip]

we needed to decide whether to include it in the charter or in the governance file

relevant: openjs-foundation/cross-project-council#1607

[jonchurch]

CPC has agreed (per @ctcpip) that this process piece does indeed belong in the Charter.md

To get CPC approval, wait to merge, batch any pending Charter changes that we may have outstanding (there's at least one other Charter change pending I believe), then get the Diff over to the CPC which will take time to review and approve by that body.

We can repurpose this PR to be a Charter change PR in general if required. cc @bjohansebas

[wesleytodd]

Changed target branch to governance-updates so that we can land these and then take one consolidated branch to the CPC for approval.

[jonchurch]

@wesleytodd private nomination is reflected in this PR, and @ctcpip we are landing these governance changes to a governance-update branch per wes' target change

Are yall's request changes review satisfied?

Im tracking the batched changes getting sent to CPC in #466 which is now on the agenda instead of the individual ones we have discussed enough times