Add node modules and compiled JavaScript from main (#54)

Co-authored-by: Oliver King <oking3@uncc.edu>

node_modules/underscore/modules/isNaN.js

@@ -0,0 +1,7 @@
+import { _isNaN } from './_setup.js';
+import isNumber from './isNumber.js';
+
+// Is the given value `NaN`?
+export default function isNaN(obj) {
+  return isNumber(obj) && _isNaN(obj);
+}