Add instructions on how to run Jasmine JS tests on the 'Running Unit Tests' page.

Review Request #8637 — Created Jan. 20, 2017 and submitted — Latest diff uploaded

Review Board
reviewboard, students
There are two types of tests that can be run to check changes or new modules,
before posting code for review. Prior to this change, the 'Running Unit Tests'
page only contained instructions on how to run tests on Python work. This
change adds instruction for how to run unit tests on work done in JavaScript.

Built the change and reviewed the resulting information and formatting on web browser.