Add options/checkbox to select other variations, rated/unrated, etc

[vitogit]

Modify this line to add more options https://github.com/vitogit/lichess-tactics-generator/blob/master/src/App.vue#L87

Add checkbox or dropbox to the page so the user can select other options

• Variations: "ultraBullet" "bullet" "blitz" "rapid" "classical" "correspondence" "chess960" "crazyhouse" "antichess" "atomic" "horde" "kingOfTheHill" "racingKings" "threeCheck"
• color: "white", "black"
• rated: true/false
• max games: 25, 50, 100

More info https://lichess.org/api#operation/apiGamesUser