Bring in CDE Staging MD content

[talkasab]

• Write a script that takes a MD file, looks to see if there's an existing definition associated with the finding
  • If no existing finding, do a standard conversion and push into the defs directory
  • If there is an existing finding, merge the existing finding with the new Markdown, reusing elements and IDs where possible
• Add the appropriate contributor
• Take into account existing IDs and synonyms