Link to GH issues in the bottom
Add build & start server to package.json

Added npm commands to package.json to build & start usermanual server:

- `npm start` uses AT.com to fetch samples
- `npm run start-dev` uses localhost.

Also I made it possible to pass `--production` and `--development` to
`build.js` because it's impossible to alter env variables in the
command that are run via `npm run-script`