Add spinner example

[FDiskas]

Overview

In some versions of community date picker the spinner mode was not working. So I added more examples to check if everything is working as aspected

react-native-datetimepicker/datetimepicker#118

[FDiskas]

Also removed yarn lock - because it locks @react-native-community/datetimepicker version. And in mane package @react-native-community/datetimepicker is peer dep. So example should always use latest version

[mmazzarolo]

@FDiskas , thanks for the PR. I updated the @react-native-community/datetimepicker version in the example's package.
I'm not merging this PR though because I'd like to keep the example code simple, and the issue you had was related to the community version being outdated.
Thanks for reporting !

[FDiskas]

Any way i thought that there should be as an example

[mmazzarolo]

Any way i thought that there should be as an example

I'm avoiding it because it's an example of something that would be subject to changes that are not in our control (community picker changes)