Remove placeholder pages or fill them with content

[TimmRuppert]

Describe the bug

While the pages creating_images.adoc, contributing_docs.adoc and compatibility.adoc are not present in the left navigation page, they can still be found via web search engines or the built in antora search function

Describe how to reproduce the bug

Steps to reproduce the behavior:

1. Go to the antora hosted doc
2. Search for Compatibility
3. See the lorem ipsum place holder text

Describe the expected behavior

Include only pages which have actual sense-full content.

Show some screenshots