PEP 1: Update language on PEP-Delegate field (#2256)

* Update language on PEP-Delegate

* Add review feedback from @JelleZijlstra and @AA-Turner

* Update pep-0001.txt

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

* Update pep-0001.txt

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

* Update pep-0001.txt

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Co-authored-by: Barry Warsaw <barry@python.org>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

pep-0001.txt

@@ -282,14 +282,25 @@ notifying the PEP author(s) and giving them a chance to make revisions.
 The final authority for PEP approval is the Steering Council. However, whenever
 a new PEP is put forward, any core developer that believes they are suitably
 experienced to make the final decision on that PEP may offer to serve as
-the PEP-Delegate for that PEP, and they will then have the authority to approve
-(or reject) that PEP. Individuals taking on this responsibility are free to seek
+the PEP-Delegate for that PEP, and they will then have the
+authority to approve (or reject) that PEP. 
+
+The term "PEP-Delegate" is used under the Steering
+Council governance model. The PEP's designated decision maker,
+the "PEP-Delegate" with the Steering Council's support, is
+recorded in the "PEP-Delegate" field in the PEP's header. For
+PEPs written prior to the Steering Council's governance model, the field name
+"BDFL-Delegate" will still be kept.
+The terms PEP-Delegate and BDFL-Delegate may be used interchangeably in 
+discussion. PEP-Delegate is the preferred term under the Steering Council 
+governance model.
+
+Individuals offering to serve as PEP-Delegate should notify the Steering
+Council, PEP authors and PEP sponsor of their intent to self-nominate.
+Individuals taking on this responsibility are free to seek
 additional guidance from the Steering Council at any time, and are also expected
 to take the advice and perspectives of other core developers into account.
 
-The designated decision maker for each PEP is recorded in the "PEP-Delegate"
-header in the PEP.
-
 Such self-nominations are accepted by default, but may be explicitly declined by
 the Steering Council. Possible reasons for the Steering Council declining a
 self-nomination as PEP-Delegate include, but are not limited to, perceptions of