Minor fixes and formatting to 2001/coupard

main() now returns a value rather than just 'return' to be more
portable.

Format/typo check README.md file.

I believe this completes the review of this entry.

2001/coupard/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-empty-body -Wno-pointer-sign -Wno-return-type -Wno-deprecated-non-prototype -Wno-implicit-int
+CSILENCE= -Wno-empty-body -Wno-pointer-sign -Wno-deprecated-non-prototype -Wno-implicit-int
 
 # Common C compiler warning flags
 #