List BDFL Delegates and target Python version in the PEP Index

[ncoghlan]

The changes to PEP 1 following the appointment of the first Steering Council have made the BDFL-Delegate role more significant, since every PEP is now expected to have a delegate appointed (even in cases where the delegate is an SC member speaking on behalf of the SC).

However, this information isn't presented in the PEP Index overview - it's only visible on the individual project pages.

Similarly, which version a PEP is targeting is very useful overview information, as a draft PEP targeting the next release (currently 3.8) needs different handling from one targeting a subsequent release.

Updating the PEP 0 generator to include that additional information would be reasonably straightforward (as it already reads in all the headers for all the PEPs), so the main complication would be to ensure that the python.org PEP index rendering doesn't break (as discussed in https://github.com/python/peps/blob/master/README.rst#generating-html-for-pythonorg )

[ncoghlan]

Reading through https://github.com/python/pythondotorg/blob/master/peps/converters.py indicates that there shouldn't be any compatibility issues that would break rendering outright, which means the key item to check for will be how a table with more columns displays at the default python.org viewport width.

[gvanrossum]

Sounds like a good idea.