Move "Advanced setup" underneath "Install" (#1732)

This frees up valuable real estate in the left ToC.

<img width="265" alt="Screenshot 2024-07-18 at 9 48 08 AM"
src="https://github.com/user-attachments/assets/b90bb6b6-da1c-4418-b65d-bbe74bee93aa">

<img width="260" alt="Screenshot 2024-07-18 at 9 48 19 AM"
src="https://github.com/user-attachments/assets/d33a251a-984e-4f76-88fa-46d2c4ae594e">

Author: Eric-Arellano

docs/guides/_toc.json

@@ -19,6 +19,19 @@
             {
               "title": "Set up an IBM Quantum channel",
               "url": "/guides/setup-channel"
+            },
+            {
+              "title": "Advanced setup",
+              "children": [
+                {
+                  "title": "Install the Qiskit SDK from source",
+                  "url": "/guides/install-qiskit-source"
+                },
+                {
+                  "title": "Configure the Qiskit SDK locally",
+                  "url": "/guides/configure-qiskit-local"
+                }
+              ]
             }
           ]
         },
@@ -29,19 +42,6 @@
         {
           "title": "Latest updates",
           "url": "/guides/latest-updates"
-        },
-        {
-          "title": "Advanced setup",
-          "children": [
-            {
-              "title": "Install the Qiskit SDK from source",
-              "url": "/guides/install-qiskit-source"
-            },
-            {
-              "title": "Configure the Qiskit SDK locally",
-              "url": "/guides/configure-qiskit-local"
-            }
-          ]
         }
       ],
       "collapsible": false