Bug - Parsing of new decorators doesn't work

In the latest work for Ember Octane, there are some new decorators that don't parse correctly. For example, if you use `@tracked` in a code sample, it doesn't render. However, we have used decorators in other parts of the guides successfully. It also seems that the processing itself hangs.

See https://github.com/ember-learn/ember-jsonapi-docs/blob/5c3d9d81107ef4ec8e1fe016de8be3c3c214121b/lib/fix-borked-yuidoc-files.js for how this was handled for other cases.