Update Visual Studio integration guide for 2019

[aaronfranke]

https://github.com/scons/scons/wiki/IDEIntegration

Visual Studio .NET 2003 / Visual Studio 2005 (Windows)

Please update this guide for Visual Studio 2019. These instructions are over a decade old, since they target Visual Studio 2005.

[mwichmann]

Willing to provide content? I'm happy to put it on the wiki since I'm able to do so, but not a VS user so can't produce the content.

[aaronfranke]

Sorry, I don't use Visual Studio much either. I was looking to get started.

[bdbaddog]

Do the instructions in the wiki for 2003/2005 work on 2019? If not, what errors do you get? More information is needed.

[mwichmann]

FYI I've tweaked the page a bit to add a TOC for easier navigation and stubs for some other IDEs (and IDE-ish editors) but didn't change the actual recipes. Great area for contributions....