sequencer - updating documentation

sequencer.sh

@@ -3,11 +3,12 @@
 # shellcheck disable=SC1090 # follow non constant source
 
 enableErrorCheck() {
-# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
+  # Do not allow use of unbound variables.
+  # Use ${VAR:-} if possibly unbound
   set -o nounset
 }
 disableErrorCheck() {
-# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
+  # Do allow the use of unbound vars.
   set +o nounset
 }