feat: add kb shortcut detection

OliverBooth.sln

@@ -28,6 +28,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ts", "ts", "{BB9F76AC-292A-
 		src\ts\Author.ts = src\ts\Author.ts
 		src\ts\TimeUtility.ts = src\ts\TimeUtility.ts
 		src\ts\UI.ts = src\ts\UI.ts
+		src\ts\Input.ts = src\ts\Input.ts
 	EndProjectSection
 EndProject
 Global

src/ts/Input.ts

@@ -0,0 +1,33 @@
+class Input {
+    public static readonly KONAMI_CODE = [
+        "ArrowUp",
+        "ArrowUp",
+        "ArrowDown",
+        "ArrowDown",
+        "ArrowLeft",
+        "ArrowRight",
+        "ArrowLeft",
+        "ArrowRight",
+        "b",
+        "a",
+        "Enter"
+    ];
+
+    public static registerShortcut(shortcut: string | string[], callback: Function) {
+        let keys: string[];
+        if (typeof shortcut === 'string') keys = shortcut.split(' ');
+        else keys = shortcut;
+
+        let sequence: string[] = [];
+        document.addEventListener('keydown', e => {
+            sequence.push(e.key);
+
+            if (sequence.slice(-keys.length).join(' ') === keys.join(' ')) {
+                callback();
+                sequence = [];
+            }
+        });
+    }
+}
+
+export default Input;

src/ts/app.ts

@@ -1,9 +1,14 @@
-import API from "./API";
+import API from "./API";
 import UI from "./UI";
+import Input from "./Input";
 
 declare const Handlebars: any;
 
 (() => {
+    Input.registerShortcut(Input.KONAMI_CODE, () => {
+        window.open("https://www.youtube.com/watch?v=dQw4w9WgXcQ", "_blank");
+    });
+
     const blogPostContainer = UI.blogPostContainer;
     if (blogPostContainer) {
         const template = Handlebars.compile(UI.blogPostTemplate.innerHTML);