message: Describe the documentation categories
diff: @@ -3,6 +3,12 @@ This folder contains the documentation for the implementation of the Enso
  programming language. The documentation is generally broken up into three
  categories: design, specification, and implementation.
  +- **Design:** Documents in this category deal with the reasoning behind the
  + language specification.
  +- **Specification:** The language specification.
  +- **Implementation:** Details of how the specification is _implemented_ in the
  + compiler and the runtime.
  +
  It is broken up into categories as follows:
  - **[Language Server](language-server/):** Documentation pertaining to the Enso
  