Update dependencies and documentation #676

Job	Run time
pkgs-linux: nixpkgs: build	1m 40s
pkgs-linux: nixpkgs: prebuilt	4m 34s
pkgs-linux: haskell-nix: build	44s
pkgs-linux: haskell-nix: prebuilt	45s
pkgs-linux: shajra: build	1m 33s
pkgs-linux: shajra: prebuilt	44s
installers-linux	15s
pkgs-darwin: nixpkgs: build	3m 1s
pkgs-darwin: nixpkgs: prebuilt	6m 33s
pkgs-darwin: haskell-nix: build	1m 51s
pkgs-darwin: haskell-nix: prebuilt	2m 36s
pkgs-darwin: shajra: build	1m 54s
pkgs-darwin: shajra: prebuilt	1m 56s
	28m 6s

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