Inconsistency between train.py and src/train.py in Readme

[alexkrz]

I am trying this great template and noticed some inconsistencies with references to train.py / src/train.py in the Readme file. I assume the train script has been moved to the src/ folder at a later stage. In my previous projects, I used to have the train and eval scripts at the root of the directory. However, I get the design choice, that you seem to want to have all python files in the src/ folder. I will draft a PR to adjust all references from train.py to src/train.py. I also noticed that the screenshot from the config overview refers to a not existing run.py script.