[WIP] Revamp standard docs, remove README contribution notes

[pacrob]

What was wrong?

Documentation across snakecharmer libraries is very varied.

Some good examples:

• I like the sections in py-evm and web3: Introduction, Quickstart, Community, and Code of Conduct
• eth-abi at least has a Welcome page

Most of the others are relatively light, if not just auto-generated or nothing at all.

This PR will collect removing stuff from the README and moving things into standardized sections of docs.

note for later - .rst code blocks can have copyable set to make it easier to copypasta for users

.. code-block:: python
   :copyable:

   def my_function():
       print("Hello, World!")

Closes #78

Cute Animal Picture

[kclowes]

As you're thinking about standardizing contributing docs, I was thinking it might be good to document the make lint-roll command in the contributor docs if you haven't already. Then maybe contributors don't need to fight as much with the linter.

[pacrob]

Many libs actually don't have docs, so also have a pattern with contribution info still in the README

[pacrob]

closed by #134