Add note about javascript code style to README.
Add note about javascript code style to README.

In particular, we want to make explicit the requirement that code
should include JSDoc comments for documentation.

Fixes #13

Review: da39a3ee5e6b4b0d3255bfef95601890afd80709@DanielSank

labrad/scalabrad-web,labrad/scalabrad-web,labrad/scalabrad-web,labrad/scalabrad-web,labrad/scalabrad-web