docs (#848)

Author: hwchase17

docs/modules/chains/generic/llm_chain.ipynb

@@ -121,10 +121,51 @@
     "llm_chain.predict(adjective=\"sad\", subject=\"ducks\")"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "672f59d4",
+   "metadata": {},
+   "source": [
+    "## From string\n",
+    "You can also construct an LLMChain from a string template directly."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "f8bc262e",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "template = \"\"\"Write a {adjective} poem about {subject}.\"\"\"\n",
+    "llm_chain = LLMChain.from_string(llm=OpenAI(temperature=0), template=template)\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "cb164a76",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "\"\\n\\nThe ducks swim in the pond,\\nTheir feathers so soft and warm,\\nBut they can't help but feel so forlorn.\\n\\nTheir quacks echo in the air,\\nBut no one is there to hear,\\nFor they have no one to share.\\n\\nThe ducks paddle around in circles,\\nTheir heads hung low in despair,\\nFor they have no one to care.\\n\\nThe ducks look up to the sky,\\nBut no one is there to see,\\nFor they have no one to be.\\n\\nThe ducks drift away in the night,\\nTheir hearts filled with sorrow and pain,\\nFor they have no one to gain.\""
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "llm_chain.predict(adjective=\"sad\", subject=\"ducks\")"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "8310cdaa",
+   "id": "9f0adbc7",
    "metadata": {},
    "outputs": [],
    "source": []