File-format brainstorming

• How to represent relationships? Candidates:
  1. Filesystem hierarchy
     • Too complex to deal with
  2. YAML metadata parent in each ${node}.md
     • Adding new nodes is single-file write operation
     • Organizing nodes en masse involves fiddling with multiple files
  3. Separate file, eg: DOT, for graphs
     • Automatically allows multi-parent nodes
       • Visually, we present one parent, while demoting others.
     • Organizing nodes en masse is easier
     • Possibility to add relationship metadata