Be more specific with guideline regarding echo >1

notes/guidelines.md

 
 ### Don't talk unless asked ###
 
-Use echo only if purpose of your script/function **is** to print.
-Otherwise use `think()` instead.
+Echo to stdout only if purpose of your script/function **is** to print
+**that** text.  Otherwise use `think()` instead.
 
 If you want to make your script "user-friendly" (like babbling about
 what it's doing), consider setting `FFOO_VERBOSE` to true in header of