Remove !menu from j k binding in initial keymap examples (#34959)

See
https://github.com/zed-industries/zed/pull/34912#issuecomment-3108802582

Release Notes:

- N/A

assets/keymaps/initial.json

@@ -13,7 +13,7 @@
     }
   },
   {
-    "context": "Editor && vim_mode == insert && !menu",
+    "context": "Editor && vim_mode == insert",
     "bindings": {
       // "j k": "vim::NormalBefore"
     }