Add link shortener to API

[austinpray]

Battle links look like https://battle.kaori.io/?in=%7B%22a%22%3A%7B%22id%22%3A1%2C%22name%22%3A%22Koshimizu+Sachiko%22%2C%22image_url%22%3A%22https%3A%5C%2F%5C%2Fstorage.googleapis.com%5C%2Fimg.kaori.io%5C%2Fstatic%5C%2Fimg%5C%2Fsachi_sketch.png%22%2C%22rarity%22%3A%22S%22%2C%22nature%22%3A%22stupid+and+horny%22%2C%22stupid%22%3A7%2C%22baby%22%3A2%2C%22clown%22%3A1%2C%22horny%22%3A6%2C%22cursed%22%3A2%2C%22feral%22%3A2%2C%22max_hp%22%3A83%2C%22dmg%22%3A18%2C%22speed%22%3A6.8339285714%2C%22crit%22%3A0.21%2C%22armor%22%3A0%2C%22evasion%22%3A0.29%7D%2C%22b%22%3A%7B%22id%22%3A2%2C%22name%22%3A%22Matt+Morgan%22%2C%22image_url%22%3A%22https%3A%5C%2F%5C%2Fstorage.cloud.google.com%5C%2Fimg.kaori.io%5C%2Fstatic%5C%2Fimg%5C%2Fmatt_morgan.jpg%22%2C%22rarity%22%3A%22S%22%2C%22nature%22%3A%22cursed+baby%22%2C%22stupid%22%3A2%2C%22baby%22%3A6%2C%22clown%22%3A1%2C%22horny%22%3A2%2C%22cursed%22%3A7%2C%22feral%22%3A2%2C%22max_hp%22%3A28%2C%22dmg%22%3A3%2C%22speed%22%3A10.075%2C%22crit%22%3A0.64%2C%22armor%22%3A1%2C%22evasion%22%3A0.69%7D%2C%22turns%22%3A%22v1.2x1E~H17~H3~E~E~E~H3~E~H3~E~H3~E~H3~E~H30C~E~E~E~H30C~E~K30C%22%7D

We need to have a link shortener that expands these