docs: update test section examples [ci skip] (#6971)
docs: update test section examples [ci skip] (#6971)

* docs: update I want to write a test section

Noticed that we encourage people to use `test-id` to query components, while `@testing-library/react-native` has different suggestions on querying components. Updated our docs to reflect to the best practices of the community 😊

* docs: added test examples
artsy/eigen,artsy/eigen,artsy/eigen,artsy/eigen,artsy/eigen,artsy/eigen,artsy/eigen