Installation instructions for PyCharm need updating

[pvcraven]

trafficstars

Installation instructions for PyCharm refer to 'requirements.txt' which is no longer a thing. This needs updating.

[cspotcode]

https://github.com/pythonarcade/template also needs to be updated.

[einarf]

It's fine to mentioned this as a simple way to store dependencies. However, the pycharm venv document is so out of date I ended up archiving it for now.