Add tealdeer module

nix/modules/tealdeer.nix

@@ -0,0 +1,13 @@
+{ config, lib, pkgs, ... }:
+
+{
+  home.packages = with pkgs; [
+    tealdeer
+  ];
+
+  home.activation = {
+    updateTLDRCache = lib.hm.dag.entryAfter ["writeBoundary"] ''
+      $DRY_RUN_CMD ${pkgs.tealdeer}/bin/tldr -u
+    '';
+  };
+}