Document rationale for relations between approaches

[samm82]

These should be done in the body of the thesis, with a link to within figure captions

TODO

• Meaning of child-parent relations: children are refinements, subsets, more concrete, and/or lower-level
• Implied relations/terms
  • Criteria for entry into spreadsheet
  • Criteria for inclusion in graphs

[samm82]

WOW this is obsolete! 😅 This has pretty much been entirely accomplished by the Terminology section; I'm closing this issue.