Add support for Relyt as a Vector Store (#13075)

docs/docs/community/integrations/vector_stores.md

docs/docs/examples/vector_stores/RelytDemo.ipynb

llama-index-cli/llama_index/cli/upgrade/mappings.json

llama-index-core/llama_index/core/command_line/mappings.json

.../vector_stores/llama-index-vector-stores-relyt/.gitignore

...tions/vector_stores/llama-index-vector-stores-relyt/BUILD

...ns/vector_stores/llama-index-vector-stores-relyt/Makefile

...s/vector_stores/llama-index-vector-stores-relyt/README.md

...vector-stores-relyt/llama_index/vector_stores/relyt/BUILD

...-stores-relyt/llama_index/vector_stores/relyt/__init__.py

...ctor-stores-relyt/llama_index/vector_stores/relyt/base.py

...tor_stores/llama-index-vector-stores-relyt/pyproject.toml

...vector_stores/llama-index-vector-stores-relyt/tests/BUILD

..._stores/llama-index-vector-stores-relyt/tests/__init__.py

...dex-vector-stores-relyt/tests/test_vector_stores_relyt.py