Fix typos in whatsapp.ipynb and telegram.ipynb (#12075)

- **Description:** 
    - Replace Telegram with Whatsapp in whatsapp.ipynb
    - Add # to mark the telegram as heading in telegram.ipynb
 
  - **Issue:** None
  - **Dependencies:** None

docs/docs/integrations/chat_loaders/telegram.ipynb

@@ -5,7 +5,7 @@
    "id": "735455a6-f82e-4252-b545-27385ef883f4",
    "metadata": {},
    "source": [
-    " Telegram\n",
+    "# Telegram\n",
     "\n",
     "This notebook shows how to use the Telegram chat loader. This class helps map exported Telegram conversations to LangChain chat messages.\n",
     "\n",

docs/docs/integrations/chat_loaders/whatsapp.ipynb

@@ -7,7 +7,7 @@
    "source": [
     "# WhatsApp\n",
     "\n",
-    "This notebook shows how to use the WhatsApp chat loader. This class helps map exported Telegram conversations to LangChain chat messages.\n",
+    "This notebook shows how to use the WhatsApp chat loader. This class helps map exported WhatsApp conversations to LangChain chat messages.\n",
     "\n",
     "The process has three steps:\n",
     "1. Export the chat conversations to computer\n",