use different desktop file rather than modify

Makefile

@@ -23,6 +23,7 @@ PKGCONFIG = $(PACKAGE).pc
 BIN = system76-keyboard-configurator
 FFI = lib$(PACKAGE).so
 APPDATA = $(APPID).appdata.xml
+TEST_LAUNCH_DESKTOP = $(APPID)launchtest.desktop
 DESKTOP = $(APPID).desktop
 ICON = data/icons/scalable/apps/$(APPID).svg
 
@@ -45,6 +46,7 @@ install:
 	install -Dm0644 target/$(TARGET)/$(FFI) "$(DESTDIR)$(libdir)/$(FFI)"
 	install -Dm0644 target/$(PKGCONFIG) "$(DESTDIR)$(libdir)/pkgconfig/$(PKGCONFIG)"
 	install -Dm0644 ffi/$(PACKAGE).h "$(DESTDIR)$(includedir)/$(PACKAGE).h"
+	install -Dm0644 "linux/$(TEST_LAUNCH_DESKTOP)" "$(DESTDIR)$(datadir)/applications/$(TEST_LAUNCH_DESKTOP)"
 	install -Dm0644 "linux/$(DESKTOP)" "$(DESTDIR)$(datadir)/applications/$(DESKTOP)"
 	install -Dm0644 "linux/$(APPDATA)" "$(DESTDIR)$(datadir)/metainfo/$(APPDATA)"
 	install -Dm0644 $(ICON) "$(DESTDIR)$(datadir)/icons/hicolor/scalable/apps/$(APPID).svg"

debian/test-launch-system76-keyboard-configurator.install

@@ -0,0 +1 @@
+usr/share/applications/com.system76.keyboardconfiguratorlaunchtest.desktop

linux/com.system76.keyboardconfiguratorlaunchtest.desktop

@@ -0,0 +1,7 @@
+[Desktop Entry]
+Name=System76 Keyboard Tester
+Exec=system76-keyboard-configurator --launch-test
+Icon=com.system76.keyboardconfigurator
+Type=Application
+StartupNotify=true
+Categories=Utility;