Main Training Script

Changes introduced in this PR:

• add speed.py script for profiling times for the dataloader under different conditions (cpu and gpu) 2be62e1f
• General cleaning of profiling code 56ceb676
• remove pre-training.py since all the implementation is already in main.py 5e156813
• Adjustments on the ground truth labels in the NYUDepthV2 class to match a batched operation for the loss evaluation. 29c5caed
• Major refactor of the main to for better parameter accessibility and logging 9de083a5
• move MODELS.md and DATASET.md to docs folder.

@pnaray2s @prange2s @sgeorg2s @adsouz2s can you please respond to this PR to make sure we are all on the same page with the changes? ... when everyone has responded I will merge to main