docs: update import paths and move to lcel for llama.cpp examples (la…

…ngchain-ai#19391)

**Description:** Update import paths and move to lcel for llama.cpp
examples
**Issue:** Update import paths to reflect package refactoring and move
chains to LCEL in examples
**Dependencies:** None

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>
Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>

docs/docs/integrations/llms/llamacpp.ipynb

@@ -208,11 +208,9 @@
    },
    "outputs": [],
    "source": [
-    "from langchain.callbacks.manager import CallbackManager\n",
-    "from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler\n",
-    "from langchain.chains import LLMChain\n",
-    "from langchain.prompts import PromptTemplate\n",
-    "from langchain_community.llms import LlamaCpp"
+    "from langchain_community.llms import LlamaCpp\n",
+    "from langchain_core.callbacks import CallbackManager, StreamingStdOutCallbackHandler\n",
+    "from langchain_core.prompts import PromptTemplate"
    ]
   },
   {
@@ -329,10 +327,10 @@
     }
    ],
    "source": [
-    "prompt = \"\"\"\n",
+    "question = \"\"\"\n",
     "Question: A rap battle between Stephen Colbert and John Oliver\n",
     "\"\"\"\n",
-    "llm.invoke(prompt)"
+    "llm.invoke(question)"
    ]
   },
   {
@@ -360,7 +358,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "llm_chain = LLMChain(prompt=prompt, llm=llm)"
+    "llm_chain = prompt | llm"
    ]
   },
   {
@@ -406,7 +404,7 @@
    ],
    "source": [
     "question = \"What NFL team won the Super Bowl in the year Justin Bieber was born?\"\n",
-    "llm_chain.run(question)"
+    "llm_chain.invoke({\"question\": question})"
    ]
   },
   {
@@ -488,9 +486,9 @@
     }
    ],
    "source": [
-    "llm_chain = LLMChain(prompt=prompt, llm=llm)\n",
+    "llm_chain = prompt | llm\n",
     "question = \"What NFL team won the Super Bowl in the year Justin Bieber was born?\"\n",
-    "llm_chain.run(question)"
+    "llm_chain.invoke({\"question\": question})"
    ]
   },
   {
@@ -710,7 +708,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.6"
+   "version": "3.9.1"
   },
   "vscode": {
    "interpreter": {