feat: HDMI refresh boost only for the display it was set up for

The EDID override moves off the kernel command line to a hotplug script
(boot unit + udev rule) that loads it only while the display it was
tested on is connected, identified over DDC; other displays get their
own EDID.

steamify.sh

@@ -15,7 +15,7 @@
 set -uo pipefail
 
 # Release version, see CHANGELOG.md.
-VERSION=2.0.3
+VERSION=2.1.0
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"