feat: Implement text manager API and database connection

- Added `text_manager.py` to handle the creation of text libraries via FastAPI.
- Introduced database connection management in `conexion.py` using PostgreSQL credentials from environment variables.
- Created abstract base class `EmbedderABC` in `Base_Embedder.py` for embedding models.
- Developed `OpenAIEmbedder` class to generate embeddings using OpenAI's API.
- Implemented `OpenAIEmbedderModel` and repository pattern for managing OpenAI embedders in `Openai_embedder_mmr.py`.
- Established `Biblioteca` class for managing text libraries and their associated notes in `biblioteca.py`.
- Created SQLAlchemy models and mappers for `Biblioteca` and `Nota` in `biblioteca_mmr.py` and `notas_biblioteca_mmr.py`.
- Added functionality for dynamic table generation for notes associated with libraries.
- Included comprehensive methods for adding, retrieving, and managing notes and libraries in their respective repositories.

backend/main.py

@@ -13,7 +13,7 @@ app = FastAPI(
 # Configuración de CORS
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=["http://localhost:5173"],  # Solo permite tu frontend local
+    allow_origins=["http://localhost:5173", "http://0.0.0.0:5173"],  # Solo permite tu frontend local
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],