I mostly made this for myself, but put it up on the Chrome store if anyone else finds it useful. If you are a user on PredictIt, you can use this plugin to group related markets in a single view to compare prices between the different markets. For example, you could group all of the 2020 presidential election "battleground" state markets in a single group to see which one gives you the best price if you think there is going to be a red/blue wave.