Support Shannon Entropy on File / Artifact Objects and not just within Windows™ PE Section Type #334
Description
Created an issue over here (oasis-open/cti-documentation#120), but seems more appropriate to track this over here instead:
Looking through Stix 2.1 documentation, it appears that only one section discusses a property of entropy which is located within a Windows™ PE Section Type (See https://docs.oasis-open.org/cti/stix/v2.1/os/stix-v2.1-os.html#_ioapwyd8oimw)
Shannon Entropy is a fundamental metric for measuring randomness in any file, not just Windows PE sections. The restriction of the entropy field to only the Windows PE Section Type in STIX 2.1 (section 6.7.6.3) seems like an arbitrary limitation
It seems more appropriate to move this field to be supported directly under File and/or Artifact objects.