Extraneous files generated

If you take a look at the examples generated, there are files generated that have no links to them and don't seem to be relevant.

For example, https://github.com/adobe/jsonschema2md/blob/master/examples/docs/simpletypes-properties.md . This file has stuff in it like `Untitled undefined type in Simple Types Schema` . But the file is not linked anywhere, and doesn't seem to be necessary.

We noticed this because we were trying to get rid of the word "untitled" in the generated docs to be able to see where we left out titles, and files like that one popped up.

Start by reproducing the generated examples and inspect examples/docs/simpletypes-properties.md, especially the “Untitled undefined type in Simple Types Schema” content and its links. Trace which generator entry point creates this unlinked file; done means the irrelevant example output is no longer generated while the relevant linked documentation remains.

Written by the indexing model from the issue text.