Clarify some texts a bit

guidelines/hierarchy.md

 
 ### relics ###
 
-If your test suite creates files that you usually need to review,
-this is a good place.  Subdirectories here should bear a timestamp in
-a human-readable and sortable timestamp format (such as ISO 8601).
+Place for locally ran tests to drop any results, reports and intermediate
+files that would be useful for investigating test failures.
+
+Subdirectories here should bear a timestamp in a human-readable and
+sortable timestamp format (such as ISO 8601).
 
 Note that normally this directory will never exist in a freshly cloned
 repository and it's likely to be excluded from version control system
 ### utils ###
 
 Any build scripts and utilities that are only useful for your project
-developers and testers.
+developers, maintainers and testers.
 
 
 ### packaging ###