Add Windows getting started guide

[coagmano]

Context: https://forums.meteor.com/t/new-meteor-com/51913/17

There are a bunch of pitfalls for new Meteor users on Windows and it would be good to have them all listed in one place so folks can avoid them.
Would also serve as an easy and authoritative answer for folks requesting Windows help.

[coagmano]

As mentioned on the forums, I've whipped up a very rough draft of a guide, and left it open for anyone to edit:
https://docs.google.com/document/d/15nTgghVHH2wZIHkmzH2sx-9vLm6OY-euv5Eqcb__ptQ/edit?usp=sharing

If anyone can help fleshing it out, add content, editing, suggestions, common issues, etc. please do!
It's currently more of an outline than anything suitable for the guide

Especially need content for WSL, since I've never got it working well either