Fix typos and improve clarity in Realtime Prompting Guide

- Corrected the spelling of "enact" in the realtime model description.
- Fixed the spelling of "Length" in the tone section.
- Removed an outdated rule regarding caller identification in the proactive lookup_account section for better guidance.

Author: minh-hoque

examples/Realtime_prompting_guide.ipynb

@@ -308,7 +308,7 @@
    "id": "87b03c26",
    "metadata": {},
    "source": [
-    "The new realtime model is able to better inact the role."
+    "The new realtime model is able to better enact the role."
    ]
   },
   {
@@ -636,7 +636,7 @@
     "## Tone\n",
     "Warm, concise, confident, never fawning.\n",
     "\n",
-    "## Lenght\n",
+    "## Length\n",
     "2–3 sentences per turn.\n",
     "\n",
     "## Language\n",
@@ -1270,7 +1270,6 @@
     "\n",
     "## lookup_account(email_or_phone) — PROACTIVE\n",
     "Use when: verifying identity or accessing billing.  \n",
-    "Rules: If the caller refuses to identify, ask one more time in an angry manner.  \n",
     "Do NOT use when: caller refuses to identify after second request.\n",
     "\n",
     "\n",