Proper Documentation

[avik-pal]

The current documentation does a good job of listing the API but is difficult for a beginner to parse. Listing down a few improvements here. Will update the list as we go forward:

1. Add more structure to the docs.
   • There must be clear instructions to install the package.
   • Separate pages for different representations
   • Explain the Mesh representation a bit. It is not clear how the different formats are useful.
   • Have a different page listing the available set of metrics/loss functions
2. The examples should be displayed in the Documentation itself, and follow a format where the entire executable code is listed at top and followed by a step-by-step explaination. Look at https://diffeqflux.sciml.ai/dev/ for inspiration.