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/xam/xam_notify.cc

@@ -32,7 +32,7 @@ dword_result_t XamNotifyCreateListener(qword_t mask, dword_t one) {
 }
 DECLARE_XAM_EXPORT1(XamNotifyCreateListener, kNone, kImplemented);
 
-// http://ffplay360.googlecode.com/svn/Test/Common/AtgSignIn.cpp
+// https://github.com/CodeAsm/ffplay360/blob/master/Common/AtgSignIn.cpp
 dword_result_t XNotifyGetNext(dword_t handle, dword_t match_id,
                               lpdword_t id_ptr, lpdword_t param_ptr) {
   if (!handle) {