Updated Stateless Mode (markdown)

Stateless-Mode.md

@@ -1 +1,47 @@
-TODO
+## Stateless Mode
+
+Configure your webserver to respond statelessly to challenges for a given account key. This requires nothing more than a one-time web server configuration change and no "moving parts".
+
+1. First get your account key thumbprint:
+
+```
+root@ed:~# acme.sh --register-account
+[Mon Feb  6 21:40:18 CST 2017] Registering account
+[Mon Feb  6 21:40:19 CST 2017] Already registered
+[Mon Feb  6 21:40:21 CST 2017] Update success.
+[Mon Feb  6 21:40:21 CST 2017] ACCOUNT_THUMBPRINT='6fXAG9VyG0IahirPEU2ZerUtItW2DHzDzD9wZaEKpqd'
+```
+
+Remember the the thumbprint in the last line:
+`
+6fXAG9VyG0IahirPEU2ZerUtItW2DHzDzD9wZaEKpqd
+`
+
+2. Configure the nginx server to return the account key thumbprint:
+
+```
+http {
+...
+  server {
+
+...
+
+    location ~ "^/\.well-known/acme-challenge/([-_a-zA-Z0-9]+)$" {
+      default_type text/plain;
+      return 200 "$1.6fXAG9VyG0IahirPEU2ZerUtItW2DHzDzD9wZaEKpqd";
+    }
+
+...
+
+  }
+}
+
+```
+
+
+3. Ok, you can issue cert now.
+
+```
+acme.sh --issue -d example.com  --stateless
+```
+