pyx: Getting Started Developing for Firefox OS Screencasts

As we are ramping up newer developers to help with the project, we need clear documentation of the development process. The Gaia/Hacking page is the canonical reference for how to do absolutely everything, but it's overwhelming. To help with this, I made a series of 5 screencasts that cover the basics of using b2g desktop nightly builds, remote debugging with b2g desktop, hacking on gaia itself in b2g desktop, flashing a phone with gaia changes, and what to do if Firefox OS asks you to choose from two homescreens or if remote debugging does not show your source for your app.