Added Solitaire in the games section.

[AadumKhor]

Added my Solitaire game project to the list.

You've read How to contribute right ?

So tell me more about your awesome contribution and add the badge to your repo after it's accepted :D

<a href="https://github.com/Solido/awesome-flutter">
   <img alt="Awesome Flutter" src="https://img.shields.io/badge/Awesome-Flutter-blue.svg?longCache=true&style=flat-square" />
</a>

[AadumKhor]

If there is any issue with the commit I've made please let me know so that it can be accepted.

[AadumKhor]

Please give some updates on this PR so that I can correct any issues.