Fix uglify example command

uglify's `-o` should point to the minified output, not to the sourcemap

Author: vanschelven

docs/platforms/javascript/common/sourcemaps/uploading/uglifyjs.mdx

@@ -17,7 +17,7 @@ First, configure UglifyJS to output source maps:
 
 ```
 uglifyjs app.js \
-  -o app.min.js.map \
+  -o app.min.js \
   --source-map url=app.min.js.map,includeSources
 ```