infospace: remove example output — will replay chapter by chapter

This commit clears the tangled example output so each chapter
can be re-committed cleanly via S3.2.

examples/infospace-with-history/output/entities/productive-powers-of-labour.md

@@ -1,30 +0,0 @@
-# Productive Powers of Labour
-
-## Definition
-
-The capacity of human labour to produce output, measured in terms of the
-quantity and quality of goods a given number of workers can produce within
-a given time. Smith argues that the division of labour is the primary cause
-of increases in productive power, and that differences in productive power
-explain differences in national wealth.
-
-## Source Chapter
-
-Book I, Chapter 1: "Of the Division of Labour"
-
-## Context
-
-Smith introduces productive powers as the dependent variable that the division
-of labour improves. He contrasts the output of an unskilled individual worker
-(one pin per day) with the output of a coordinated team under division of
-labour (4,800 pins per person per day) to demonstrate the scale of improvement.
-
-## Economic Domain
-
-Production
-
-## Smith's Original Wording
-
-"This great increase in the quantity of work, which, in consequence of the
-division of labour, the same number of people are capable of performing, is
-owing to three different circumstances."