The script reads a config file from:
	1.	~/.gaming-mode.conf (user override), or
	2.	/etc/gaming-mode.conf (system-wide default)

Available options

# How Steam launches:
#   bigpicture → steam -tenfoot (default)
#   gamepadui  → steam -gamepadui
STEAM_LAUNCH_MODE=bigpicture

# Performance tweaks:
#   enabled  → enable gamescope low-latency flags and perf tweaks
#   disabled → run in a more conservative mode
PERFORMANCE_MODE=enabled

You can create the file manually or copy from an example:

sudo cp docs/gaming-mode.conf.example /etc/gaming-mode.conf
sudo $EDITOR /etc/gaming-mode.conf

(User-specific overrides should go in ~/.gaming-mode.conf.)