cli[patch], google-vertexai[patch]: readme template (#16470)

libs/cli/langchain_cli/integration_template/README.md

@@ -1 +1,45 @@
 # __package_name__
+
+This package contains the LangChain integration with __ModuleName__
+
+## Installation
+
+```bash
+pip install -U __package_name__
+```
+
+And you should configure credentials by setting the following environment variables:
+
+* TODO: fill this out
+
+## Chat Models
+
+`Chat__ModuleName__` class exposes chat models from __ModuleName__.
+
+```python
+from __module_name__ import Chat__ModuleName__
+
+llm = Chat__ModuleName__()
+llm.invoke("Sing a ballad of LangChain.")
+```
+
+## Embeddings
+
+`__ModuleName__Embeddings` class exposes embeddings from __ModuleName__.
+
+```python
+from __module_name__ import __ModuleName__Embeddings
+
+embeddings = __ModuleName__Embeddings()
+embeddings.embed_query("What is the meaning of life?")
+```
+
+## LLMs
+`__ModuleName__LLM` class exposes LLMs from __ModuleName__.
+
+```python
+from __module_name__ import __ModuleName__LLM
+
+llm = __ModuleName__LLM()
+llm.invoke("The meaning of life is")
+```