Walkthrough in core lib #21
Description
Eventually, we should enable the walkthrough in the core library.
When G-S has processed a page, and found a GS-suitable table, it should check if the user has already seen the walkthrough.
If the user hasn't seen the walkthrough, introduce them to G-S. Include a toggle at the start and end of the walkthrough that indicates "do not show me this walkthrough again".
The walkthrough will be centered on the first G-S toggle on the page.