Add P0 integration and control add-in guidance

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 02baffe8-0600-430d-81fa-a9993685e7cb

microsoft/knowledge/web-services/webhook-eligibility-and-validationtoken-renewal.good.js

@@ -0,0 +1,11 @@
+function receiveBusinessCentralWebhook(request, response) {
+    const validationToken = request.query.validationToken;
+
+    if (typeof validationToken === "string") {
+        response.status(200).type("text/plain").send(validationToken);
+        return;
+    }
+
+    processNotifications(request.body.value);
+    response.sendStatus(200);
+}