Add readme

Author: adribaeza

README.md

@@ -212,7 +212,7 @@ The root directory contains configuration files and documentation for the overal
 
 6. Go to `http://localhost:8000/docs` to access the FastAPI Swagger documentation of the backend.
 
-### Usage
+### Frontend usage
 
 1. Enter your message in the chat interface on the Streamlit application.
 2. Click the "Send" button to send the message to the backend API.
@@ -231,6 +231,15 @@ The interface send all history of the chat to the backend API to generate the re
 
 For clear the chat history, you can click the "New Chat" button.
 
+### Backend API Usage
+
+The backend API is a FastAPI application that handles the chatbot logic and interacts with the TinyLlama model to generate responses. The API exposes the following endpoints:
+
+- **POST /api/v1/chat**: This endpoint receives a chat messages from the frontend and generates a response using the TinyLlama model. View swuaager documentation in `http://localhost:8000/docs` for more information.
+
+- **GET /docs**: This endpoint provides the Swagger documentation for the backend API. You can access it by going to `http://localhost:8000/docs` in your web browser.
+
+
 ### Building the Docker Image Locally
 
 To build the Docker image for the backend FastAPI application, run the following command: