v0.2.0 - nanoserde Support

New Features

• Added nanoserde support via feature flag for minimal builds
• Smaller binary size and faster compilation with nanoserde backend
• Backward compatible - existing code works unchanged

Usage

• Default: tinykv = "0.2" (uses serde)
• Minimal: tinykv = { version = "0.2", default-features = false, features = ["nanoserde"] }

Thanks to Beautiful_Lilly21 for the suggestion!