Move app install scripts to /usr/bin

overlay/usr/bin/install_firefox.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+echo "**** Installing/upgrading Firefox via flatpak ****"
+
+# Install Firefox
+flatpak --user remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo 
+flatpak --user install --assumeyes --or-update flathub org.mozilla.firefox
+
+# Configure Firefox as the default browser
+echo "Configure Firefox..."
+custom_webbrowser="$(cat <<EOF
+"libraryfolders"
+[Desktop Entry]
+NoDisplay=true
+Version=1.0
+Encoding=UTF-8
+Type=X-XFCE-Helper
+X-XFCE-Category=WebBrowser
+X-XFCE-CommandsWithParameter=${USER_HOME:?}/.local/share/flatpak/exports/bin/org.mozilla.firefox "%s"
+Icon=org.mozilla.firefox
+Name=org.mozilla.firefox
+X-XFCE-Commands=${USER_HOME:?}/.local/share/flatpak/exports/bin/org.mozilla.firefox
+EOF
+)"
+if [[ ! -f "${USER_HOME:?}/.local/share/xfce4/helpers/custom-WebBrowser.desktop"  ]]; then
+    mkdir -p "${USER_HOME:?}/.local/share/xfce4/helpers"
+    echo "${custom_webbrowser}" > "${USER_HOME:?}/.local/share/xfce4/helpers/custom-WebBrowser.desktop"
+    gio mime x-scheme-handler/http org.mozilla.firefox.desktop
+fi
+
+echo "DONE"