Appservice registration section includes an unhelpful auto-generated example

**Link to problem area**: https://spec.matrix.org/v1.6/application-service-api/#registration

**Issue**
The spec talks about YAML files, and even has a hand-crafted example for the registration. The JSON example is not providing value in this section.

Start at the linked application-service registration section and locate its source in the specification repository. Compare the hand-crafted YAML example with the auto-generated JSON example, then verify the rendered section no longer includes the unhelpful JSON example.

Written by the indexing model from the issue text.