Update releasenotes.md

Author: bradharding

releasenotes.md

@@ -18,6 +18,7 @@
   * The frames per second are now shown if a `HELP` or `HELP1` lump from a PWAD is displayed.
 * Focus is now given to your browser when using the `license`, `releasenotes` or `wiki` CCMDs.
 * The MIDI music of the free versions of [*SIGIL*](https://romero.com/sigil) and [*SIGIL II*](https://romero.com/sigil) now play as intended.
+* A bug is fixed whereby binding the `+supershotgun` action to a control, and then using that control, would cause the player to jump rather than equip their super shotgun.
 
 ![](https://github.com/bradharding/www.doomretro.com/raw/master/wiki/bigdivider.png)