Add release changelog.
Add release changelog.

adamlwgriffiths/Pyglet,adamlwgriffiths/Pyglet,seeminglee/pyglet64,adamlwgriffiths/Pyglet,adamlwgriffiths/Pyglet,seeminglee/pyglet64,niklaskorz/pyglet,seeminglee/pyglet64,niklaskorz/pyglet,niklaskorz/pyglet,niklaskorz/pyglet