Merge pull request #877 from immae/mdbook

Dependencies

• [2] WFJGOVMJ Merge branch 'master' of github.com:NixOS/hydra into master
• [3] 7HFOCQ2H Remove nix from hydra-perl-deps
• [4] RWNXH3H2 lastModified -> lastModifiedDate
• [5] 3JXCTKEC Add markdown files for documentation

Change contents

• edit in flake.nix at line 244
  [3.38]→[2.95:95](∅→∅)
  −