[ruby/pstore] Enhanced RDoc

https://github.com/ruby/pstore/commit/c12560e59a

lib/pstore.rb

@@ -38,7 +38,14 @@ require "digest"
 # == About the Examples
 #
 # Examples on this page need a store that has known properties.
-# Therefore examples may assume the existence of this helper method:
+# They can get a new (and populated) store by calling thus:
+#
+#   example_store do |store|
+#     # Example code using store goes here.
+#   end
+#
+# The implementation of +example_store+
+# (which is profoundly unimportant here):
 #
 #   require 'pstore'
 #   require 'tempfile'
@@ -56,12 +63,6 @@ require "digest"
 #     yield store
 #   end
 #
-# This means that example code can look like this:
-#
-#   example_store do |store|
-#     # Example code using store goes here.
-#   end
-#
 # == The Store
 #
 # The contents of the store are maintained in a file whose path is specified