Move chat guide to existing Artificial Intelligence section

Author: tpayet

docs.json

@@ -379,6 +379,7 @@
               {
                 "group": "Artificial intelligence",
                 "pages": [
+                  "guides/ai/getting_started_with_chat",
                   "guides/ai/mcp",
                   "guides/embedders/openai",
                   "guides/langchain",
@@ -421,13 +422,6 @@
                   "guides/vercel"
                 ]
               },
-              {
-                "group": "AI",
-                "pages": [
-                  "guides/ai/getting_started_with_chat",
-                  "guides/ai/mcp"
-                ]
-              },
               {
                 "group": "Miscellaneous",
                 "pages": [