Corrected Sentence in router.ipynb (#9377)

Added missing question marks in the lines in the router.ipynb

@baskaryan @hwchase17

docs/extras/modules/chains/foundational/router.ipynb

@@ -195,7 +195,7 @@
       "\n",
       "\n",
       "\u001b[1m> Entering new MultiPromptChain chain...\u001b[0m\n",
-      "math: {'input': 'What is the first prime number greater than 40 such that one plus the prime number is divisible by 3'}\n",
+      "math: {'input': 'What is the first prime number greater than 40 such that one plus the prime number is divisible by 3?'}\n",
       "\u001b[1m> Finished chain.\u001b[0m\n",
       "?\n",
       "\n",
@@ -206,7 +206,7 @@
    "source": [
     "print(\n",
     "    chain.run(\n",
-    "        \"What is the first prime number greater than 40 such that one plus the prime number is divisible by 3\"\n",
+    "        \"What is the first prime number greater than 40 such that one plus the prime number is divisible by 3?\"\n",
     "    )\n",
     ")"
    ]
@@ -342,7 +342,7 @@
       "\n",
       "\n",
       "\u001b[1m> Entering new MultiPromptChain chain...\u001b[0m\n",
-      "math: {'input': 'What is the first prime number greater than 40 such that one plus the prime number is divisible by 3'}\n",
+      "math: {'input': 'What is the first prime number greater than 40 such that one plus the prime number is divisible by 3?'}\n",
       "\u001b[1m> Finished chain.\u001b[0m\n",
       "?\n",
       "\n",
@@ -353,7 +353,7 @@
    "source": [
     "print(\n",
     "    chain.run(\n",
-    "        \"What is the first prime number greater than 40 such that one plus the prime number is divisible by 3\"\n",
+    "        \"What is the first prime number greater than 40 such that one plus the prime number is divisible by 3?\"\n",
     "    )\n",
     ")"
    ]