Editor: fix toggleDark in separate script tag

Author: pepc84

editor/index.html

@@ -257,7 +257,8 @@
 </div>
 </div>
 <footer><p>C++ Mode for Processing</p><p class="footer-contact"><a href="mailto:pep84c@gmail.com">pep84c@gmail.com</a></p></footer>
-<script src="../assets/nav.js">
+<script src="../assets/nav.js"></script>
+<script>
 let darkMode = false;
 function toggleDark() {
   darkMode = !darkMode;