doc: how to use advanced features of `configure` on Windows

[refack]

Refs: #17066

The configure script recognizes many CLI flags for special build formulas. Many are not represented by vcbuild shortcuts, and need to be passed either by:

• Calling python configure --XXX --YYY=PPPP directly, followed by vcbuild noprojgen
• Setting set config_flags=--XXX --YYY=PPPP before calling vcbuild

This should be documented.

Can I take this up?

[joyeecheung]

@lazyspark Sure! The contributing guide should be enough to help you get started.

[juggernaut451]

@lazyspark if you are not working on this.. can i take this up? @joyeecheung @refack

Yes please.

[jake32321]

Hey @juggernaut451 are you still working on this? If not, I could try and take a shot if you don't have the time. Don't want this to change hands too many times but would love to take a crack at this if you don't mind.

[refack]

I was thinking about this today and had the idea of calling python configure --help as part of the help subrutine in vcbuild.bat

[jake32321]

@refack yeah that should be simple enough to make that addition.

[rexagod]

@refack @jake32321 Can I take this up? Thanks!

[refack]

Hello @rexagod, and thanks for the offer.
AFAICT this issue is available for "adoption", so I'd be very grateful if you take this up.

If you haven't already, it's recommended you take a look at CONTRIBUTING.md
Anyway thank you for the contribution, and good luck 🥇

P.S. If you have any questions feel free to contact me directly.