Template: Clarify what the point is

[terichadbourne]

This is a duplicate of the issue already fixed on the Vanilla implementation, now moving over to the template so we can use the updates everywhere.

• - Cover key concepts such as Offline First, Service Workers, etc. (can be pulled from tutorial)
• - Explain why Offline First makes an app (in this case, a shopping list app) more useful through the lens of user experience
• - Explain that syncing can be used across multiple devices (laptop, phone, tablet) or users
• - Explain why the stack used in this implementation is well suited to Offline First tech
• - Place tutorial section to above fold (if it exists)
• - Place live demo above fold (if it exists)
• - Clarify that what they're seeing is a "reference implementation" - just code
• - Make it clear that the "Steps" are for viewing the app as an end user, NOT for building the app
• - Add "and explored the code in this GitHub repo" after "When the reader has completed this Code Pattern" so that promise about learning becomes true
• - Offer alternative (eg if you're not already familiar with React, you may want to check out this Vanilla JS...)

(This issue is written so that we can apply it to the template as well - not all checklist items are relevant to the vanilla version.)