docs: split SDKs and SQL into two pages, promote to Getting Started

SQL now leads with why you'd reach for it beyond analytics: it's served over
Flight SQL, so it's the way in for any language without a native LanceDB SDK,
and broadly every public SDK method has a corresponding SQL statement. Closes
by pointing at the SQL Reference as the spec that defines the precise
behavior behind both the SQL surface and the SDK operations it mirrors.

Moving both into Getting Started (before Agentic Skills) means a reader knows
what the API surface even is before being told how to hand it to an agent.

docs/web/docs.json

@@ -230,6 +230,10 @@
     {
       "source": "/troubleshooting",
       "destination": "/deployment/support"
+    },
+    {
+      "source": "/basics/apis",
+      "destination": "/basics/sdk"
     }
   ],
   "navigation": {
@@ -243,6 +247,8 @@
               "index",
               "quickstart",
               "architecture",
+              "basics/sdk",
+              "basics/sql",
               "basics/agentic-skills"
             ]
           },
@@ -256,8 +262,7 @@
               "basics/jobs",
               "tables/consistency",
               "basics/guarantees",
-              "basics/limits",
-              "basics/apis"
+              "basics/limits"
             ]
           },
           {