Nimble setup does not work
### Problem
Running ``nimble setup`` does not work because it tries to find a .uproject in a folder that does not exist. It also looks for the uproject under the engine folder. I validated the json file, the "gameDir" points to the folder where the uproject is located. And engine dir is correct aswell.

### Reproduce:
Create a new Unreal Engine 5 c++ project (I use 5.1).
Wait for compilation to finish.
Clone the plugin into ``Plugins\NimForUe\``.
Set paths in ``NimForUe.win.json``.
Run ``nimble setup``.

And that is where I get this error.

![image](https://github.com/jmgomez/NimForUE/assets/100090490/61753175-0671-46f5-bc16-8eb7e9b11e25)
(everything after ``Engine\Source\`` does not exist, it is my gameDir)

It seems to append part of ``gameDir`` onto ``engineDir`` and look for a project there.