nimsuggest doesn't run on a fresh choosenim Windows install
Came across this issue as it breaks the VSCode Nim extension on Windows ([see issue](https://github.com/saem/vscode-nim/issues/97))

Steps to reproduce:

* Install choosenim using runme.bat on a Windows 10 machine
* Once it's installed, try running `nimsuggest` on the command line
* Observe the following error message

![image](https://user-images.githubusercontent.com/54367524/173307214-6651ef58-1b55-4618-9e2a-a1c7331126b3.png)

The DLL in question is not copied over from `.choosenim/toolchains/mingw64/bin` into `.nimble/bin` which might be the source of the issue. I think nimsuggest must assume there is a global MinGW installation in the PATH. This appears not to be an issue for the nim compiler `nim`, maybe because it doesn't directly access the DLLs but goes through choosenim's own MinGW proxies?

Current workaround: Adding `.choosenim/toolchains/mingw64/bin` manually to the global PATH works, but ofc this is not ideal since it kinda defeats the point of choosenim

Possible solution: Append `~/.choosenim/toolchains/mingw64/bin` to the process PATH before each execution

