feat(nix): add yarn

Signed-off-by: Seongmin Lee <boltlessengineer@proton.me>

authored by boltless.me and committed by boltless.me 0c4c251b fa14b6f9

Changed files
+1
nix
+1
nix/flake.nix
··· 66 66 pkgs.gopls 67 67 pkgs.hello 68 68 pkgs.janet 69 + pkgs.yarn 69 70 pkgs.jpm 70 71 pkgs.meld 71 72 pkgs.mprocs