docs(readme): Document createUnsignedAssertion()

Author: Eva Sarafianou

README.md

@@ -6,6 +6,8 @@ Create SAML assertions. Supports SAML 1.1 and SAML 2.0 tokens.
 
 ### Usage
 
+#### Signed Assertions
+
 ```js
 var saml = require('saml').Saml20; // or Saml11
 
@@ -20,14 +22,42 @@ var options = {
     'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name': 'Foo Bar'
   },
   nameIdentifier: 'foo',
-  sessionIndex: '_faed468a-15a0-4668-aed6-3d9c478cc8fa'
+  sessionIndex: '_faed468a-15a0-4668-aed6-3d9c478cc8fa',
 };
 
-var signedAssertion = saml.create(options);
+saml.create(options, (err, samlAssertion) => {
+  if (err) { throw new Error(err) }
+  console.log(samlAssertion)
+})
 ```
 
 Everything except the cert and key is optional.
 
+#### Unsigned Assertions
+
+```js
+var saml = require('saml').Saml20; // or Saml11
+
+var options = {
+  issuer: 'urn:issuer',
+  lifetimeInSeconds: 600,
+  audiences: 'urn:myapp',
+  attributes: {
+    'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress': '[email protected]',
+    'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name': 'Foo Bar'
+  },
+  nameIdentifier: 'foo',
+  sessionIndex: '_faed468a-15a0-4668-aed6-3d9c478cc8fa',
+};
+
+saml.createUnsignedAssertion(options, (err, samlAssertion) => {
+  if (err) { throw new Error(err) }
+  console.log(samlAssertion)
+})
+```
+
+All options are optional
+
 ## Issue Reporting
 
 If you have found a bug or if you have a feature request, please report them at this repository issues section. Please do not report security vulnerabilities on the public GitHub issue tracker. The [Responsible Disclosure Program](https://auth0.com/whitehat) details the procedure for disclosing security issues.