Add an option to create one markdown file per card

[GSGBen]

It might be cleaner in certain cases to have a single markdown file per card, containing the description, checklists, comments and attachment list.

• [x] work out why the attachment section is writing out of order
  • I was awaiting the wrong task
• [x] Fix missing attachment section in UE4/UMG _ UI/Get position of nested widget to set another widget in a canvas to it's screen position
  • UpdateAttachmentReferencesAsync() was using the original description, not reading the new appended-to one from disk
• [x] check the output of the previous (file count and contents) and new
• [x] copy some into obsidian and check the formatting