dev work for hybrid

docs/examples/hybrid-layer.ipynb

poetry.lock

pyproject.toml

semantic_router/__init__.py

semantic_router/encoders/__init__.py

semantic_router/encoders/base.py

semantic_router/encoders/bm25.py

semantic_router/encoders/cohere.py

semantic_router/encoders/huggingface.py

semantic_router/encoders/openai.py

semantic_router/encoders/tfidf.py

semantic_router/layer.py

semantic_router/rankers/cohere.py

semantic_router/retrievers/__init__.py

semantic_router/retrievers/bm25.py

semantic_router/schema.py