feat: appimage package script

revert: flutter lock file

build_appimage.py

@@ -1,8 +1,11 @@
 #!/usr/bin/python3
 import os
 
-
-
 if __name__ == '__main__':
-
-    pass
+    os.chdir("appimage")
+    ret = os.system("appimage-builder --recipe AppImageBuilder.yml --skip-test")
+    if ret == 0:
+        print("RustDesk AppImage build success :)")
+        print("Check AppImage in '/path/to/rustdesk/appimage/RustDesk-VERSION-TARGET_PLATFORM.AppImage'")
+    else:
+        print("RustDesk AppImage build failed :(")