Change title of section 4.5.3 from "Manifest Content Originator" to "Manifest Author"

Current wording

** 4.5.3. Manifest content originator**

Permalink

https://standards.internetofproduction.org/pub/okh#manifest-content-originator

Proposal

Change the title of this section to:

4.5.3 Manifest Author

Motivation

This section refers to the manifest-author field in the manifest so it would be better for the section title to match the manifest field name.