Updated readme

README.md

@@ -1,3 +1,19 @@
 # Dotfiles
 
-My NixOS configuration.
+My NixOS configuration.
+
+## Usage
+
+Clone the repository to some directory. `/etc/nixos/git` in this example.
+
+Set up `configuration.nix`:
+```nix
+{ ... }:
+
+{
+    imports = [
+        ./hardware-configuration.nix
+        ./git/machines/[machine].nix
+    ];
+}
+```