Update documentation.

- Convert http to https, provide archive link when possible.
- Made CPU-JIT.png more readable on dark themes;
Added a white background so there isn't black text on a black
background.

src/xenia/kernel/xobject.cc

@@ -385,7 +385,7 @@ object_ref<XObject> XObject::GetNativeObject(KernelState* kernel_state,
     return object;
   } else {
     // First use, create new.
-    // http://www.nirsoft.net/kernel_struct/vista/KOBJECTS.html
+    // https://www.nirsoft.net/kernel_struct/vista/KOBJECTS.html
     XObject* object = nullptr;
     switch (as_type) {
       case 0:  // EventNotificationObject