Release 6.0.0

SemVer major release to pull changes since the last release. The main motivations for the release are:

• Add Napi::Object::TypeTag() and Napi::Object::CheckTypeTag() methods.
• Set operator napi_callback_info explicit.
• Some minor fixes all over the test suite.
• Add tests related to Napi::Object::TypeTag() and Napi::Object::CheckTypeTag() methods.
• Add tests related to Napi::CallbackScope.
• Add tests related to Napi::EscapableHandleScope.
• Add tests related to Napi::Maybe<T>.
• Add tests related to Napi::ThreadSafeFuntion.
• Change some tests related to Napi::AsyncWorker.
• Add documentation for Napi::Object::TypeTag() and Napi::Object::CheckTypeTag() methods.
• Add documentation about how to run a specific unit test.

What's Changed

• test: Add test covg for Maybe by @JckXia in #1270
• test: Add tests for ThreadSafeFunction's NonBlock function overloads by @JckXia in #1249

Full Changelog: v5.1.0...v6.0.0