Fix example, `to` should be `path`

[bradyt]

Before:

dart example/main.dart
Diff algorithm found changes: [{op: replace, path: /test, value: 6}, {op: replace, path: /object/list/2, value: 4}, {op: replace, path: /object/child, value: 5}]
Unhandled exception:
Patch field "path" is missing.
#0      JsonPatch._extractPath (package:json_patch/src/json_patch.dart:304:7)
#1      JsonPatch._applyOne (package:json_patch/src/json_patch.dart:279:20)
#2      JsonPatch.apply (package:json_patch/src/json_patch.dart:223:16)
#3      main (file:///private/tmp/dart-json-patch/example/main.dart:23:31)
#4      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:297:19)
#5      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)

Fix:

modified   example/main.dart
@@ -31,7 +31,7 @@ void main() {
           'path': '/test',
           'value': {'child': 'value'}
         },
-        {'op': 'move', 'from': '/test', 'to': '/moved'},
+        {'op': 'move', 'from': '/test', 'path': '/moved'},
       ],
       strict: true,
     );

After:

dart example/main.dart
Diff algorithm found changes: [{op: replace, path: /test, value: 6}, {op: replace, path: /object/list/2, value: 4}, {op: replace, path: /object/child, value: 5}]
Object after applying patch operations: {a: 5, moved: {child: value}}