Add 'Observation:' to the get_weather function

unit1/dummy_agent_library.ipynb

@@ -401,7 +401,7 @@
       "source": [
         "# Dummy function\n",
         "def get_weather(location):\n",
-        "    return f\"the weather in {location} is sunny with low temperatures. \\n\"\n",
+        "    return f\"Observation: the weather in {location} is sunny with low temperatures. \\n\"\n",
         "\n",
         "get_weather('London')"
       ]