Suggestion: Allow file display minimisation in PR interface

[AlexCppns]

Some fairly long diffs are not as important to read (eg fixtures used for testing), I wish I had a button to minimise some of the files

[cirosantilli]

Do you mean to be able to hide a hunk? (here lines containing group :test, etc...

[Mottie]

Our GitHub-Dark (user)script adds a diff toggle button - ref. Hmm, I probably should separate that code out into a separate userscript.

[sindresorhus]

Duplicate of #514.

You might want to check out the refined-github browser extension which adds support for this.