doc: add a breaking change file with documentation for the renaming of attestation

Context

This MR adds a new file in the documentation. This file contains the breaking changes to come in the upcoming protocol or Octez version to inform the users on the changes to be made.

Manually testing the MR

Check the produced artifact of the documentation

Checklist

• n/a Document the interface of any function added or modified (see the coding guidelines)
• n/a Document any change to the user interface, including configuration parameters (see node configuration)
• n/a Provide automatic testing (see the testing guide).
• n/a For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR