Added 2 files: Contributing Guide and Improving Written Communication

Changes:

Created improving-written-communication.md which includes tips and tools for better written communication
Created contributing.md that includes GitHub markdown and forking/PR guides
Changed community-development folder to community-development-resources
Added a really rough start to the Wiki page based on the Ring Charter Template.
Added a how-to-listen.md section to the community-development-resources.
Added a brief blurb in the README.md explaining what it means to "opt-in" to the CoC.

ethereum-magicians / integrity-ring