Improve --push-target example in README

A common use case for the --push-target option is to pass the device
Download directory.

README.md

@@ -667,7 +667,7 @@ There is no visual feedback, a log is printed to the console.
 The target directory can be changed on start:
 
 ```bash
-scrcpy --push-target /sdcard/foo/bar/
+scrcpy --push-target=/sdcard/Download/
 ```