Add 1 liner to codex prompting guide (#2236)

Author: anoop-openai

examples/gpt-5-codex_prompting_guide.ipynb

@@ -6,6 +6,9 @@
    "metadata": {},
    "source": [
     "## GPT-5-Codex Prompting Guide\n",
+    "\n",
+    "_This guide can also be used for `GPT-5.1-Codex` and `GPT-5.1-Codex-Mini`, we recommend to keep the same prompts and harness for `GPT-5.1-Codex` and `GPT-5.1-Codex-Mini` as `GPT-5-Codex`_\n",
+    "\n",
     "Important details about `GPT-5-Codex` and this guide:\n",
     "- This model is not a drop-in replacement for GPT-5, as it requires significantly different prompting.\n",
     "- This model is only supported with the Responses API and does not support the verbosity parameter.\n",