Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15143
## Summary
Adds a RocksDB blog post describing the native async/coroutine read APIs introduced in RocksDB 11.10.0. It covers the callback and `folly::coro::Task` interfaces, differences from `ReadOptions::async_io`, executor and I/O-completion handoffs, filesystem integration, request-local statistics across suspension, and API lifetime constraints.
The post includes three explanatory diagrams and benchmark results comparing synchronous and coroutine point reads across task counts and `MultiGet` batch sizes.
https://www.internalfb.com/intern/px/p/cDGqv/
Reviewed By: xingbowang
Differential Revision: D117159178
fbshipit-source-id: 5452e6b07e29abb5594505021995e9b5bac9d198