fix: Update Core connection documentation format

- Clarify that for Core connections, full URL (scheme, host, port) comes from url parameter
- Address GitHub comment feedback about misleading connection string format

Co-Authored-By: [email protected] <[email protected]>

Author: devin-ai-integration[bot]

src/firebolt_db/firebolt_dialect.py

@@ -145,7 +145,7 @@ def create_connect_args(self, url: URL) -> Tuple[List, Dict]:
         """
         Build firebolt-sdk compatible connection arguments.
         URL format : firebolt://id:secret@host:port/db_name
-        For Core: firebolt://host:port/db_name?url=core_url
+        For Core: firebolt://db_name?url=http://localhost:8080 (full URL in url parameter)
         """
         parameters = dict(url.query)