Clarify the PEP-Delegate process

[warsaw]

As pointed out in this ticket, the process for PEP-Delegate selection in PEP 1 needs to be updated. @willingc has agreed to submit a PR.

[pradyunsg]

I'd like to flag that it might be useful to clarify how standing delegations for BDFL-Delegate work as well. Currently, there are standing delegations for Packaging PEPs (https://github.com/python/steering-council/blob/master/process/standing-delegations.md). OTOH, it might make sense to defer further clarification in this area until PEP 609 is put forward for the Steering Council's review.

[brettcannon]

@pradyunsg nothing changes for any preexisting delegations. And packaging PEPs are entirely special based on how they are managed, so I don't think they are worth calling out now, especially if PEP 609 may change things on its own.

[AA-Turner]

With #2256 and #2257, this has now been done.

A