Anthropic README updates

libs/partners/anthropic/README.md

@@ -1 +1,66 @@
 # langchain-anthropic
+
+This package contains the LangChain integration for Anthropic's generative models.
+
+## Installation
+
+`pip install -U langchain-anthropic`
+
+## Chat Models
+
+| API Model Name     | Model Family   |
+| ------------------ | -------------- |
+| claude-instant-1.2 | Claude Instant |
+| claude-2.1         | Claude         |
+| claude-2.0         | Claude         |
+
+To use, you should have an Anthropic API key configured. Initialize the model as:
+
+```
+from langchain_anthropic import ChatAnthropicMessages
+from langchain.schema import AIMessage, HumanMessage
+model = ChatAnthropicMessages(model="claude-2.1", temperature=0, max_tokens=1024)
+```
+
+# Define the input message
+
+`input_message = HumanMessage(content="What is the capital of France?")`
+
+# Generate a response using the model
+
+`response = model.invoke(input_message)`
+
+# Using Messages
+
+You can also use a list of messages to generate a response. This is useful for multi-turn conversations.
+
+```
+model = ChatAnthropicMessages(
+    model="claude-2.1",
+    temperature=0,
+    max_tokens=1024
+    )
+```
+
+# Define the input messages
+
+```
+messages = [
+{"role": "system", "content": "You are a helpful assistant."},
+{"role": "user", "content": "What is the capital of France?"},
+]
+
+```
+
+### Generate responses using the model
+
+`responses = model.generate(input_messages)`
+
+# Embeddings
+
+Anthropic does not offer its own embedding model. However their documentation offers solutions using Voyage AI.
+[Anthropic Embeddings Documentation](https://docs.anthropic.com/claude/docs/embeddings)
+
+## Multimodal inputs
+
+Currently, Anthropic models do not support direct multimodal inputs through this package.