Refactor README (reorder installation steps + color-formatting for commands)

[ankitaS11]

This PR updates the README, notably following changes have been made:

1. Re-formatted the codes to have bash like color-formatting.
2. Reordered installation to include linux installation command -> git clone repo -> conda environment creation -> cmake building -> run tests.
3. Use $nproc instead of hard-coding 16 in the cmake –build command.

cc: @certik

[certik]

We should add zlib into the Conda environment, that should take care of it.

The binutils are currently needed for stacktraces on Linux --- I'd like to get rid of it and move fully to the same approach as macOS is using which does not require binutils, but I didn't have time to finish it yet.

[ankitaS11]

We should add zlib into the Conda environment, that should take care of it.

Good point @certik, fixed it.

The binutils are currently needed for stacktraces on Linux --- I'd like to get rid of it and move fully to the same approach as macOS is using which does not require binutils, but I didn't have time to finish it yet.

That makes sense, I can work on this and create a separate PR if it is okay with you. :)

[certik]

I don't have $nproc defined. Is the -j16 confusing?

We could switch to ninja, which runs in parallel by default.

[ankitaS11]

May be $nproc doesnot work on Mac, the reason it was confusing to me was that I only had 8 cores in my CPU but it had hardcoded 16 in the readme, but I guess it wouldn't matter much as it will always take 8 cores if that's the maximum count.

I can revert this change, may be switching to ninja is an option but IMO not something thats needed right now.

[certik]

Thanks! Very useful.

[certik]

Thanks!