Write the README, API reference, storage guide, examples, and support policy

[kylebernhardy]

Outcome

Provide the documentation developers expect from an independent open-source native library.

Acceptance criteria

• README covers installation, native and Rocks usage, supported platforms, quick starts, lifecycle, errors, cancellation, and operational expectations.
• API reference documents schemas, mutations, search modes, scores, pagination, highlighting, status, metrics, and close behavior.
• Rocks guide documents caller ownership, compatible rocksdb-js versions, durability, backups, recovery, and generation cleanup.
• Examples include standalone native, standalone rocksdb-js, multiple indexes, phrase/fuzzy/autocomplete, and graceful shutdown.
• Performance methodology, benchmark history, semantic-versioning policy, security reporting, contribution instructions, and support matrix are linked.
• Harper-specific schema and query documentation remains owned by Harper rather than duplicated here.

Comment generated by kAIle (Codex GPT-5)