[GNC-dev] Customising Transaction Report

[flywire]

I probably should have added this comment in the source code. I'm not clear
how the Transaction Report relates to a derived report:
https://github.com/Gnucash/gnucash/blob/maint/gnucash/report/trep-engine.scm#L491

  ;; (Feb 2018) Note to future hackers - this gnc:trep-options-generator
  ;; defines a long set of options to be assigned as an object in
  ;; the report. This long list (52 at Feb 2018 count) of options
  ;; may be modified in a derived report (see income-gst-statement.scm)
  ;; via gnc:make-internal! and gnc-unregister-option to hide
  ;; and remove options, respectively. If an option is unregistered,
  ;; don't forget to re-register them via gnc:register-option, unless
  ;; your derived report truly does not require them.