Add more documentation to the preloader

docs/assets/js/constants.js

@@ -1,5 +1,19 @@
 var constants = {
     testOrganizer: {
         EXAMPLE_DELETE_ME_LATER : 1277336
+    },
+    ui: {
+        // These are the variables that control injection/cssinjector.js
+        // To add a new theme var, you must also add it to the injector
+        theme: {
+            webpage: {
+                bg_color: "#242424",
+                text_color: "#ffffff",
+                canvas_border: "rgb(63, 63, 63)"
+            },
+            game: {
+                
+            }
+        }
     }
 };

docs/assets/js/preloader/preloader.js

@@ -1,3 +1,26 @@
+/**
+ * This file contains the code that powers the full-screen loading animation.
+ * Multiple animations can be created in the same webpage, and toggled individually.
+ * 
+ * --- Usage ---
+ * let myPreloader = new Preloader();
+ * 
+ * // Show the loader
+ * myPreloader.show(true);
+ * 
+ * // load some stuff
+ * // ...
+ * 
+ * // Fade out the animation
+ * myPreloader.hide(false);
+ * 
+ * --- How it works ---
+ * On creation, the Preloader injects some HTML into the webpage with a unique ID 
+ * for the instance. Hiding and showing works by modifying the active classes for 
+ * the loader. The "appear" and "disappear" classes will render their respective 
+ * animations in _sass/ui/page_loader.scss
+ */
+
 let preloaderCount = 0;
 
 /**