ensure lp group membership and parport kernel modules in install-deps

txt2printr.sh writes directly to /dev/lp0, which needs the lp kernel
driver loaded (via parport/parport_pc) and lp group membership for
non-root write access; wire both up during dependency install.

install-deps.sh

@@ -1,3 +1,13 @@
 #/bin/bash
 ./yay-installer.sh
 yay -Syu fswebcam ascii-image-converter
+
+# lp group membership grants write access to /dev/lp0 for txt2printr.sh
+if ! groups "$USER" | grep -qw lp; then
+    sudo usermod -aG lp "$USER"
+    echo "Added $USER to the lp group - log out and back in for this to take effect"
+fi
+
+# parport/parport_pc expose the parallel port as /dev/lp0 via the lp driver
+sudo modprobe parport parport_pc lp
+echo -e "parport\nparport_pc\nlp" | sudo tee /etc/modules-load.d/parport.conf > /dev/null