v0.2.0

Re-export every external crate that appears in the public API so that users
no longer have to add the same dependencies to their own Cargo.toml simply
to make this crate's macros and traits compile.

Added

• Crate-root re-exports of aws_config, aws_smithy_runtime_api,
  aws_smithy_types, opentelemetry, opentelemetry_sdk, and
  opentelemetry_semantic_conventions.
• Crate-root re-exports of tracing, tracing_subscriber, and
  tracing_opentelemetry, gated on the tracing-backend feature.
• lambda::LambdaError and lambda::LambdaEvent convenience aliases for
  lambda_runtime::Error and lambda_runtime::LambdaEvent.
• The lambda module now publicly re-exports lambda_runtime (previously
  #[doc(hidden)]).
• New "Re-exported crates" section in the crate-level documentation.

Changed

• aws-config moved from dev-dependencies to dependencies, with the
  behavior-version-latest feature pinned. The make_lambda_runtime! and
  aws_sdk_config_provider! macros now reference aws-config through the
  crate's re-export, so users no longer need to depend on aws-config
  directly.
• opentelemetry_sdk is now re-exported at the crate root rather than only
  inside the lambda module, matching its use in non-Lambda public APIs.
• Documentation examples updated to use the convenience aliases
  LambdaError / LambdaEvent and the re-exported lambda_runtime path.

Notes

• Users still need to declare these as direct dependencies: the aws-sdk-*
  service crates they use, tokio (the #[tokio::main] proc-macro emitted
  by make_lambda_runtime! resolves tokio by absolute path), and
  serde_json for typical Lambda event types.