Contract Headers

[threepwave]

I ran through all of the settling_game contracts and added a standard header.

I tried to keep it lightweight and simple so it wouldn't require a ton of overhead. Just a quick synopsis for those new to the repo or who haven't touched a file in a while.

The format I started with is:

# Contract title
#   Contract Description Line 1
#   Contract Description Line 2
#
# License

In practice this looks like (e.g. imodules.cairo):

# Module Interfaces 
#   These are interfaces that can be imported by other contracts for convenience.
#   All of the functions in an interface must be @view or @external.
# 
# MIT License

Would love any and all feedback here!

I also started an issue with a set of contracts that I didn't feel knowledgeable enough to write the title / description for so would appreciate if people can pick off contracts they're familiar with in the docs/header branch.

[ponderingdemocritus]

This is A+

Perhaps we have a standard for indicating what other modules that module has write access to?

[threepwave]

I like this idea. How often does this change? If it's pretty easy to maintain, I think we should place it right before the license with something like

# write -> S07_Crypts.cairo