Add colmena to shell.nix, add lorri envrc

.envrc

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# the shebang is ignored, but nice for editors
+
+if type -P lorri &>/dev/null; then
+  eval "$(lorri direnv)"
+else
+  echo 'while direnv evaluated .envrc, could not find the command "lorri" [https://github.com/nix-community/lorri]'
+  use nix
+fi

shell.nix

@@ -2,5 +2,6 @@
 pkgs.mkShell {
   packages = with pkgs; [
     hcloud
+    colmena
   ];
 }