The existing shebang doesn't work in fish. Changing so that it acknowledges and respects earlier advice from dt that we should *never* use /bin/sh in scripts because people assume bash. The existing script wouldn't work in anything but bash shell.

.config/sxiv/exec/key-handler

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 # Example for $XDG_CONFIG_HOME/sxiv/exec/key-handler
 # Called by sxiv(1) after the external prefix key (C-x by default) is pressed.