add oil keymap

plugins/default.nix

@@ -4,6 +4,7 @@
     ./cmp.nix
     ./lsp.nix
     ./mini.nix
+    ./oil.nix
     ./treesitter.nix
   ];
 

plugins/oil.nix

@@ -0,0 +1,15 @@
+{config, lib, ...}: {
+  plugins.oil = {
+  };
+  # add this keymaps only if oil plugin is enabled
+  keymaps = lib.mkIf config.plugins.oil.enable [
+    {
+      action = "<cmd>Oil<CR>";
+      key = "-";
+      options = {
+        silent = true;
+        # TODO what does silent do?
+      };
+    }
+  ];
+}