Added example usage to README

ghost/members-ssr/README.md

@@ -11,6 +11,44 @@ or
 
 ## Usage
 
+```js
+const MembersSSR = require('./');
+
+const {
+    exchangeTokenForSession,
+    getMemberDataFromSession
+} = MembersSSR({
+    cookieMaxAge: 1000 * 60 * 60 * 24 * 184, // 184 days max cookie age (default)
+    cookieSecure: true, // Secure cookie (default)
+    cookieName: 'members-ssr', // Name of cookie (default)
+    cookiePath: '/', // Path of cookie (default)
+    cookieKeys: 'some-coole-secret', // Key to sign cookie with
+    membersApi: membersApiInstance // Used to fetch data and verify tokens
+});
+
+require('http').createServer((req, res) => {
+    if (req.method.toLowerCase() === 'post') {
+        exchangeTokenForSession(req, res).then(() => {
+            res.writeHead(200);
+            res.end();
+        }).catch((err) => {
+            res.writeHead(err.code);
+            res.end(err.message);
+        });
+    } else {
+        getMemberDataFromSession(req, res).then((member) => {
+            res.writeHead(200, {
+                'Content-Type': 'application/json'
+            });
+            res.end(JSON.stringify(member));
+        }).catch((err) => {
+            res.writeHead(err.code);
+            res.end(err.message);
+        });
+    }
+}).listen(3665);
+```
+
 
 ## Develop