Standard properties annotations

[lua-vr]

Annotate the character position of elements and objects in the AST (like Org does). I'm constantly reminded of this since I think this would be extremely useful. Some applications:

• Paragraph-accurate "synctex" in organon (perhaps even split AST into words like pandoc does)
• Support for org-remark (marginalia) annotations via the templates
• Support for Org line-number links (not a priority, I don't like this sort of link)

[lua-vr]

Changing towards the more general goal of supporting the new org-element--standard-properties plist