Programming steps: /// Step: markers in function bodies and exec blocks
render as numbered step tables and flowcharts, with Graphviz or Mermaid,
and an opt-in pssparser checker (SPSS001) finds plain // Step: comments to
convert. Activity diagrams: pss:activity-diagram draws an action's activity
as a UML activity diagram, with an outline as its text form, and
:activity-diagram: puts it in autopss entries. Steps marked in an activity
become regions of its diagram and give a compound action a step table, once
pssparser attaches comments to activity statements.