Add examples for client certificate content

Author: ArchangelSDY

articles/azure-web-pubsub/howto-client-certificate.md

@@ -155,6 +155,10 @@ module.exports = async function (context, req) {
       var certThumbprint = null;
       if (req.body.clientCertificates) {
           certThumbprint = req.body.clientCertificates[0].thumbprint;
+          // Certificate content in PEM
+          var certContent = req.body.clientCertificates[0].content;
+          var cert = new crypto.X509Certificate(certContent);
+          console.log('Client cert:', cert);
       }
       if (certThumbprint != validCertThumbprint) {
           context.log('Expect client cert:', validCertThumbprint, 'but got:', certThumbprint);

articles/azure-web-pubsub/reference-cloud-events.md

@@ -103,7 +103,8 @@ ce-eventName: connect
     "subprotocols": [],
     "clientCertificates": [
         {
-            "thumbprint": "ABC"
+            "thumbprint": "<certificate SHA-1 thumbprint>",
+            "content": "-----BEGIN CERTIFICATE-----\r\n...\r\n-----END CERTIFICATE-----"
         }
     ]
 }