Another thing to keep in the back of your mind (if you don't mind more unsolicited advice) is that you are building something that is the base for plugins. For it to be as successful as Sublime is, the core has to be rock solid and be made up of core features only. Be careful with feature creep. And consider putting things that you may not feel are part of that core into plugins initially (think vintage in Sublime). If they are, then migrate them over.
(I promise, no more telling you how to oversee your project!)
Btw why are the Linux and Mac versions both 21mb but the Windows version is only 1mb? Magic? I'm gonna assume magic.
Also: it doesn't seem to use Electron! Cool! But wait, it uses Python + Qt instead?
The Windows version is an online installer that always fetches the latest version from the update server. It's based on Google Omaha, the same technology that also Chrome uses for auto-updating. I wrote a blog post about this [1].
It uses PyQt instead of Electron. I was very tempted to use Electron, but its startup time is prohibitive. I wrote a blog post about this as well [2].
[1]: https://fman.io/blog/google-omaha-tutorial/
[2]: https://fman.io/blog/picking-technologies-for-a-desktop-app-...