Migration Guide Asks / Meta tracking Bug

[gauntface]

GoogleChrome/workbox#757

[addyosmani]

For the migration guide, we should walk through what is involved in taking a site using sw-precache and sw-toolbox over to using workbox-sw and build. I've asked if we can explore this as a codelab initially but an accompanying article with FAQs/best practices during the move might also make sense.

[gauntface]

@addyosmani do you have any example projects that could be used for testing this guide?

I.e. Take example X, run through the guide and see if all questions were answered. No repeat for project Y and Z.