Update README and docs to show this works with Nim 1.2 and Godot 3.2
Hi I just followed the instructions for the Godot Nim stub with Nim v1.2 and Godot 3.2.1 stable and was able to run the example.  So far so good. 

I'm new to Nim and Godot, but it seems like the lack of updates to the docs, might scare people into thinking Nim isn't viable with Godot.  Can you update the README and docs?