Detailed Explanation: User Stories are not required in the Product Backlog as per the Scrum Guide. The Product Backlog is a collection of all work to be done on the product, and it can include a variety of formats, such as tasks, features, and technical requirements, not just user stories.

In TDD you start with writing the test before the code. This test cannot pass. If it does, the test is wrong. When the tests are written, the production code to satisfy the test will be written. Once all the tests succeeds, the product code is done.

Refinement meeting and release planing are no scrum events. The others are, and they are all about feedback:
inspection and adaptation. (And in order for the inspection to have a good outcome, the artifacts need to be transparent)

Detailed Explanation: Product documentation can be part of a Done Increment if it adds value and meets the Definition of Done. Scrum does not prescribe documentation but emphasizes delivering value to stakeholders.

In TDD you start with writing the test before the code. This test cannot pass. If it does, the test is wrong.
When the tests are written, the production code to satisfy the test will be written. Once all the tests succeeds, the product code is done.