Identify breaking changes

[codeboten]

It would be great if there was automation in place to provide maintainers of the configuration repo with an indication of a breaking change. I'm not sure if there's already tooling out there to accomplish this, but the proto repository uses bufio to identify breaking changes in the proto. Maybe something like it is available for json schema?

At the very least, this issue should be used to document some guidelines in the review process for maintainers/approvers to follow. Something along the lines of:

• when there are breaking changes to the example files, ensure the changes are documented as breaking
• ensure file format version numbers are incremented for breaking changes
• ...

It might be useful for this repository to include example files for the different versions of the schema, this would allow users/implementers to have this available for testing as well.