Add kitty-launcher.desktop to handle URL scheme for Linux

setup.py

@@ -967,6 +967,23 @@ TryExec=kitty
 Exec=kitty
 Icon=kitty
 Categories=System;TerminalEmulator;
+'''
+            )
+    with open(os.path.join(deskdir, 'kitty-launcher.desktop'), 'w') as f:
+        f.write(
+            '''\
+[Desktop Entry]
+Version=1.0
+Type=Application
+Name=kitty URL Launcher
+GenericName=Terminal emulator
+Comment=Open URLs with kitty
+TryExec=kitty
+Exec=kitty +open %U
+Icon=kitty
+Categories=System;TerminalEmulator;
+NoDisplay=true
+MimeType=x-scheme-handler/kitty;
 '''
             )