Update CONTRIBUTING.md (#345)

CONTRIBUTING.md

@@ -49,7 +49,7 @@ please read these instructions carefully.
 For a contribution to be accepted:
 
 - Follow the [Style Guide] when writing the code;
-- Format the code using `flutter format .`;
+- Format the code using `dart format .`;
 - Documentation should always be updated or added (if applicable);
 - Examples should always be updated or added (if applicable);
 - Tests should always be updated or added (if applicable) -- check the [Test writing guide] for
@@ -169,4 +169,4 @@ There are a few things to think about when doing a release:
 [conventional commit]: https://www.conventionalcommits.org
 [fork guide]: https://guides.github.com/activities/forking/#fork
 [PRs]: https://github.com/SimformSolutionsPvtLtd/flutter_calendar_view/pulls
-[gitmoji]: https://gist.github.com/parmentf/035de27d6ed1dce0b36a
+[gitmoji]: https://gist.github.com/parmentf/035de27d6ed1dce0b36a