Fixed first line

assignments/ReportingForDuty.md

@@ -4,6 +4,6 @@ Be sure to *git update* before, and be sure to *git commit* and *git push* after
 
 - Don Brutzman
 
-Changed "mile" in first line to "file."
+Changed "mile" in the first line to "file."
 
 - Jonathan Boron