Stop `expand-all-collapsed-code` with `esc` #2939

1. Visit https://github.com/microsoft/TypeScript/commit/55218d64a58a9964229daa0a38bdfb0a6be717e5#diff-46fd87925e4552c166ec188712741c3f

2. Alt-click the "expand up" button

   <img width="438" alt="expand up" src="https://user-images.githubusercontent.com/1402241/77653158-b364c480-6f6f-11ea-8b04-5d874305d210.png">

3. Grow a beard while the remaining 20000 lines are loaded 20 at a time

I wish that pressing esc would stop the load (i.e. inside the observer, if !continueLoading, disconnect) https://github.com/sindresorhus/refined-github/blob/3b7c0deded048ec14076e782c89511a3c59b46dc/source/features/expand-all-collapsed-code.tsx#L8