Getting-started doc for Windows compilation

I have been trying to get an example going for Windows, using console tools. Details below showing my incomplete working. Once we get this right, could we add to docs?

My currently-broken build line,
```
cl /I"C:\saga\023.libsoundio\libsoundio-1.1.0\soundio" sine.c gdi32.lib opengl32.lib kernel32.lib user32.lib shell32.lib /link /LIBPATH:C:\saga\023.libsoundio\libsoundio-1.1.0\x86_64
```

Some issues to cover in a doc for a console guide,
* Remind user to launch the Developer Command Prompt
* Create a batch file
* Indicate correct system 'lib' files (there are probably redundancies above)
* Indicate how to set libpath and include path

Should the zip distribution include a ".lib" file?

Once this is done, turn around and do same for a recent Visual Studio. Related issue, #49.