Docs feedback: Improve documentation on the development environment for Windows

I'm trying to build GitLab Runner on Windows 10x64, but I'm lost now.

After having installed Go and Docker for Windows I still cannot build. The setup is now lacking GCC which is hidden somewhere at Win Builds. What's next??

Please add a concise documentation describing the steps to be able to build GitLab (Runner) on Windows machines qickly and without ado. I doesn't make sense to study all the different foreign development packages for hours just to be able to fix bugs in GitLab (Runner).

BTW: Visual Studio should be the preferred compiler to be used by Go on Windows. So, if the steps would be describing how to use VC++ with Go, that would be a Plus.