feat(ThinkPad): Added sops and 1-st key

Also have an instruktion for sops

host/ThinkPad/secrets/secrets.nix

@@ -0,0 +1,14 @@
+{
+  sops = {
+    age.keyFile = "/root/age.key";
+
+    secrets = {
+      wallhaven = {
+        format = "binary";
+        sopsFile = ./wallhaven.pem;
+        owner = "kirill";
+        mode = "0400";
+      };
+    };
+  };
+}