correct comment spelling

Author: pdabelf5

exampleSite/static/njs/echo.js

@@ -23,5 +23,5 @@ function echo(r) {
 	return r.return(200, JSON.stringify(response));
 }
 
-// uncomment for us in NJS
+// uncomment for use in NJS
 // export default { echo }

exampleSite/static/njs/greet.js

@@ -2,5 +2,5 @@ function hello(r) {
     return r.return(200, "Hello world!");
 }
 
-// uncomment for us in NJS
+// uncomment for use in NJS
 // export default { hello }