How to setup dev environment

[alan-palacios]

Hi! I've been using sidebery and it's great. Unfortunately I have some issues where new tabs are being placed in the wrong panel.
I want to check what is the problem myself but had some problems running the browser with addon as there isn't a webext.run.mjs script as declared in the package.json: "dev.run": "node build/webext.run.mjs --dev", and it's not being generated with the npm run dev command neither.
I'm missing some previous setup?

[mbnuqw]

Sorry, I forgot to update .gitignore file, now fixed.