Publish a page with FAQs to address common questions re how Electric Next is different from the previous Electric

[alco]

On Discord, we're seeing people ask similar questions regarding the local-first or offline capabilities of Electric Next, how to sync data to a local database, what clients are supported, etc. We can address those questions that follow the theme "how can I do X in Electric Next when in the previous Electric it was builtin?" where X is any of

• managing migrations (migrations proxy is no longer needed)
• syncing to local DB
• syncing local writes to the server
• electrifying Postgres schema
• scaling the number of users, the size of synced data, etc.

We can also preempt a bunch of questions about performance and capabilities that fall out naturally from the docs we've put out in the open so far:

• what are some concrete benchmarks that back our scalability claims?
• how does authorization work?
• how does PGlite fit into the picture of syncing with Electric Next?

The aim of having a decidated FAQ page is to provide quick answers to very specific questions as opposed to asking everyone to read through a wall of text on our About page or a hypothetical Architecture page.