Document raw table improvements

[simolus3]

This adds documentation for raw table improvements shipped in version 0.4.11 of the core extension.

This includes:

1. Options to generate triggers and put / delete statements automatically (the docs explain both approaches now).
2. How to enable local-only columns with inferred statements.
3. An overview of different migration techniques using the new powersync_trigger_resync() SQL function.

TODOs:

• Update min version numbers for SDKs.