Add content address descriptors (CADs) for the methods in goblin chat

This adds Content Address Descriptors (CADs) to Goblin Chat. Each method has their cad defined in the cad.rkt file, that is imported and used. Each CAD come in two "pairs" one with a suffix :cad which is a struct containing the method name and description and then one without the cad: which is just the method name (the method name in this case is referring to the cadified method name).

The pull request also includes a lot of utils which could at a later date be refactored into its own library so other programs could use them, or re-written. These utils have been seperated from the method descriptions and put into the cad-utils.rkt file.

Lastly you can generate a web UI to view these cads, you can do so by running the main module in the cad.rkt file.