I downloaded this and tried it out, but it seems to hide all the implementation details. What if we need to make some changes to index.html? For example, I want

I downloaded this and tried it out, but it seems to hide all the implementation details. What if we need to make some changes to index.html? For example, I want to make a game like Untrusted (https://alexnisnevich.github.io/untrusted/ https://alexnisnevich.github.io/untrusted/) but to do so I need to be able to create a textbox for code editing next to the game canvas. Is this possible to do under ct.js?