Rich attributes: Add documentation on ReadTheDocs

[ITAYC0HEN]

We're all extremely excited for the Rich Attributes addition on MWDB. I believe it is important that once out, it will be thoroughly documented on the official docs. This includes:

• Presentation of the feature
• Use cases
• Examples with code
• Release a few implementations of basic (and probably very common) examples
  • Basic/Detailed PE information
  • Virus Total Replication that will be retrieved from VT (Detection rate, static info, related files, suggested_threat_label, imphash, first submission, ...)