docs: expand RaBitQ ecosystem references - #91

Summary

• clarify that the listed systems adopt or draw inspiration from the RaBitQ algorithm, not necessarily this library
• add Microsoft DiskANN, LanceDB, Databricks, ClickHouse, Qdrant, and Weaviate
• document DiskANN's spherical-quantization terminology and the relationship of Qdrant and Weaviate to RaBitQ
• link each new entry to official documentation or source code

Verification

• confirmed all newly added links resolve successfully
• ran git diff --check