Fix last commit; support running from extracted appimage

Author: blahgeek

scripts/AppRun

@@ -1,14 +1,13 @@
 #!/bin/bash
 
 # https://docs.appimage.org/packaging-guide/environment-variables.html#id2
-
-APPIMAGE_ROOT="$APPDIR"
-
 unset APPDIR
 unset APPIMAGE
 unset OWD
 unset ARGV0
 
+APPIMAGE_ROOT="$(dirname "$(readlink -f "$0")")"
+
 VERSION=$(readlink "$APPIMAGE_ROOT/bin/emacs" | sed -e 's/emacs-//')
 
 export EMACSLOADPATH="$APPIMAGE_ROOT/share/emacs/$VERSION/lisp"