[FR]: Add compatibility table to README

Describe the problem

Neither README.md nor any top-level doc states the minimum SDK, required Kotlin version, or compatible Compose BOM range. New consumers cannot tell if the library supports their target configuration before trying to integrate.

Describe the solution

Add a compatibility table to README.md with:

• minSdk
• Minimum Kotlin version
• Compose BOM version the library is built against

Additional context

Priority: High. Effort: XS.