Improving community notifications for RFCs

[brianraymor]

• Delete references to This week in DCP
• Use #dcp-announce[ments] instead of #dcp channel for rfc state changes

[brianraymor]

@HumanCellAtlas/dcp-pm-team - I'd prefer not to create another slack channel for the moment. Until there is more progress with the proposed Communications team, I'd prefer to delete references to This week in DCP, continue using #dcp, keep this issue open, and move the RFC process to approval.

If the Communications team is not funded, then PM will need to address some of that charter scope which may include a This week in DCP mailing list.

[brianraymor]

Will re-open if a Communications team is created.