Please see my changes to the core.md

[igarousi]

Here is a list of my changes:

• Cleaned up json codes to ensure curly brackets were correct.
• Merged date created, date modified, and date published because they share a similar example. We may want the same approach for the creator, provider, and publisher.
• Removed the "createdworkstatus" property from the SubjectOf example and defined it in its section.
• Added an example for open-ended date ranges for the temporal coverage property.
• Extended the media object definition and the associated media section. This is the main change.
• Used identifier instead of URL to show the relations for HasPart and IsPartOf sections. Also, I modified their examples.
• Reordered the last three rows of the table to be consistent with the context.
• Added internal links for core.md. Also, I added a reference section for one of the properties. If accepted, we can do the same for other properties.