ES6 modules and static json

Somewhat related to paul90's dat wiki experiments. Can we reduce server administration in the federation close to zero?

The changes to support dat included renaming wiki pages to include the `.json` suffix.

ES6 modules can be imported from any URL.

We could remove dependency upon npm for packaging.

Also interested to think about loading external plugins with SES:

Observable has guidance about how to import modules that adhere to different generations of Javascript module conventions into its pages: