feat(home-manager): add local directories to PATH

This adds local `vendor/bin` and `node_modules/.bin` directories to my
`PATH` so I can more quickly and easily run binaries within a project
from within those directories without needing to include the path.

system/nixos/home-manager.nix

@@ -29,6 +29,7 @@ in
     LANG = "en_GB.UTF-8";
     LC_ALL = "en_GB.UTF-8";
     LC_CTYPE = "en_GB.UTF-8";
+    PATH = "$PATH:./vendor/bin:./node_modules/.bin";
     PULUMI_SKIP_UPDATE_CHECK = "true";
     RIPGREP_CONFIG_PATH = "$HOME/.config/ripgrep/config";
   };