Added Sound as a separate menu topic

docs/en/en.json

@@ -411,6 +411,19 @@
                     }
                 ]
             },
+            {
+                "name": "SOUND",
+                "items": [
+                    {
+                        "path": "/manuals/sound",
+                        "name": "Sound"
+                    },
+                    {
+                        "path": "https://defold.com/assets/fmod/",
+                        "name": "FMOD"
+                    }
+                ]
+            },
             {
                 "name": "INPUT",
                 "items": [
@@ -458,6 +471,10 @@
                     {
                         "path": "/manuals/debugging-game-logic",
                         "name": "Debugging"
+                    },
+                    {
+                        "path": "/manuals/writing-code",
+                        "name": "Writing code"
                     }
                 ]
             },