is there a way to know where the "game list" is located?

[TheMirkMan]

it would be cool that instead of waiting for an update that adds a game, i can just go to a folder, write a little bit of code and add my own game with my own image

[jpleau]

https://github.com/NintenZone/SwitchRPC/blob/000d120cce3d33303aa69041b03277d24e9aa27f/index.js#L27

Points to https://nintenbot.js.org/rpc.json

So technically you could edit that JS file and supply your own JSON.