Add automation interface for blurbit

[larryhastings]

Mariatta needs a utility function for her blurb-on-the-web project. The function should be something like:

def format_blurb_filename(section, bpo_no, body, date=None)

and it should return the filename relative to the Python root.

[Mariatta]

GitMate.io thinks possibly related issues are python/core-workflow#189 (Add CONTRIBUTING.md), python/devguide#3 (Add Travis support), python/devguide#172 (Add PDF build), python/core-workflow#32 (Add the mention bot?), and python/devguide#292 (Add linkcheck to CI).

[larryhastings]

Yeah well GitMate.io can SIT AND SPIN

[Mariatta]

Thanks Larry, so actually I will need the filename returned with out the slash in front.
So just Misc/News.d/.....

[hugovk]

@Mariatta Is this still needed? If so, how does #43 look?

Otherwise let's close the issue and PR :)