Add Project README

[cowboyd]

The @effection/contrib package is designed to be a warehouse of curated, emerging helpers for dealing with very common tasks encountered while using Effection.

The goal is to be both a useful repository of modules that we can point to whenever someone asks a question that can solve there problem, but also serve as an educational tool.

Once we are confident that a module in contrib really does represent the "right" way to do things, then the module can graduate to it's own package, or even effection core (in the case where it works with a standard API like workers or websockets)

We need a README that will

1. Explain the reason @effection/contrib exists
2. Provide an index to all of the individual modules with a brief explainer on what problem they solve.
3. describe the best way to use contrib modules and what to expect from them and their place in the ecosystem (emerging techniques) without scaring them away.
4. Invite contribution

[taras]

Provide an index to all of the individual modules with a brief explainer on what problem they solve.

Do we want this to be manually entered for each module?

[cowboyd]

I think we should start by manually entering it for each module, but eventually, and sooner rather than later, we would parse the markdowns Of each individual module and use some structure there to compile an index in the main read me during each release process