Add some documentation

Author: FWest98

README.md

@@ -31,7 +31,9 @@ $provider = new \OpenIDConnectClient\OpenIDConnectProvider([
         'publicKey'               => 'file:///myproj/data/public.key',
 
         // Alternatively, you can use automatic discovery as long as your server
-        // has the <issuer>/.well-known/openid-configuration endpoint
+        // has the <issuer>/.well-known/openid-configuration endpoint.
+        // This endpoint will then provide all provider settings above, so you only need to provide
+        // your own clientId, clientSecret, and redirectUri.
         'issuer'                  => 'http://example.com/oauth2'
     ],
     [

example/client.php

@@ -9,15 +9,24 @@
     [
         'clientId' => 'demoapp',
         'clientSecret' => 'demopass',
-        'idTokenIssuer' => 'brentertainment.com',
         // Your server
         'redirectUri' => 'http://localhost:8082/',
+
+        // Settings of the OP (OpenID Provider)
+        // The issuer of the identity token (id_token) this will be compared with what is returned in the token.
+        'idTokenIssuer' => 'brentertainment.com',
         'urlAuthorize' => 'http://brentertainment.com/oauth2/lockdin/authorize',
         'urlAccessToken' => 'http://brentertainment.com/oauth2/lockdin/token',
         'urlResourceOwnerDetails' => 'http://brentertainment.com/oauth2/lockdin/resource',
         // Find the public key here: https://github.com/bshaffer/oauth2-demo-php/blob/master/data/pubkey.pem
         // to test against brentertainment.com
         'publicKey' => $key,
+
+        // Alternatively, you can use automatic discovery as long as your server
+        // has the <issuer>/.well-known/openid-configuration endpoint.
+        // This endpoint will then provide all provider settings above, so you only need to provide
+        // your own clientId, clientSecret, and redirectUri.
+        // 'issuer' => 'http://example.com/oauth2' // This is not supported by the brentertainment.com service
     ],
     [
         'signer' => $signer,