How to Prove integers with sum of 10 trick? Stuck on something obvious

Have you tried Doom Emacs or Spacemacs? They are pre-configured Emacs that use Vim keybindings. I think Org Mode comes with them (or can be installed by adding a line to the config), along with plugins that make it easier to work with files. There’s also an Org Mode thread.

I used Spacemacs for a while but then switched to a custom configuration after watching this video.

I’m not sure if it was already mentioned somewhere, but this post is interesting. I think it uses Vim and some custom scripts.