Add support for automatic TLS certificates via Let's Encrypt. Add a

configuration reference to the README.md file.

config.json.example

@@ -8,6 +8,9 @@
     "db_name": "headscale",
     "db_user": "foo",
     "db_pass": "bar",
+    "tls_letsencrypt_hostname": "",
+    "tls_letsencrypt_cache_dir": ".cache",
+    "tls_letsencrypt_challenge_type": "HTTP-01",
     "tls_cert_path": "",
     "tls_key_path": ""
 }