Error in main readme: we provide train.py and evaluate.py scripts to train and evaluate

[robmarkcole]

Issue

In Reproducibility with Lightning it states we provide train.py and evaluate.py scripts to train and evaluate but as far as I can see these files do not exist. The correct instructions are in the v0.5.0 release notes.

I also spotted reference to train.py in a few experiments, and that may require updating.

Fix

Wanted to check my understanding before making a PR

[adamjstewart]

Correct, the new torchgeo (or python -m torchgeo) script is the replacement for train.py.

I also noted this in #1196. We should probably copy that whole section of the release notes to the README, as the CLI isn't documented at all right now.

Feel free to submit a PR to add just the script stuff or all of #1196. Otherwise I'll definitely get to it before the next patch release.