You can even add TODO lists in an issue. So each one could be an issue, and then you could add the steps you want to accomplish in the description.
Step 1 Get Othello working no matter what means possible. Focus on ES5 and vanilla javascript if possible.
Step 2 Refactor game so that you are not using global variables, you are not copying pasting any code chunks, and think about scalability and memory management.
Step 3 Refactor code again to use Jquery and ES6.
Step 4 Refactor Code and write game in React.
Convert each item below into one or more issues.
You can even add TODO lists in an issue. So each one could be an issue, and then you could add the steps you want to accomplish in the description.