Fix link to sql page (#3326)

# Description of Changes

As title said

# Expected complexity level and risk
1

# Testing
- [x] Run `check link`

---------

Signed-off-by: Tyler Cloutier <[email protected]>
Co-authored-by: Tyler Cloutier <[email protected]>

Author: mamcx

docs/docs/sql/pg-wire.md

@@ -21,7 +21,7 @@ implemented, or behave differently:
 
 - **Protocol Version**: Only *PGWire* protocol *version 3.0* is supported, and only the *Simple Query Protocol*, and
   without parameterized queries.
-- **SQL Features**: Only the subset of SQL features documented in the [SQL documentation](index.md) are
+- **SQL Features**: Only the subset of SQL features documented in the [SQL documentation](/docs/sql) are
   supported. Subscription queries do not update in real time.
 - **Authentication**: SpacetimeDB does not implement database users or roles. The connection string
   `user_name@database_name` ignores `user_name`; only `database_name` is used. Authentication is based on the *auth