Fixed: typo in help CLI command.

Author: evilebottnawi

bin/npm-run-all/help.js

@@ -35,7 +35,7 @@ Options:
                                unlimited.
     --npm-path <string>  - - - Set the path to npm. Default is the value of
                                environment variable NPM_EXECPATH.
-                               If the variable is not defined, then it's "npm."
+                               If the variable is not defined, then it's "npm".
                                In this case, the "npm" command must be found in
                                environment variable PATH.
     -l, --print-label  - - - - Set the flag to print the task name as a prefix