Acrolinx: Fix typos in MQTT endpoint configuration guide

Author: denrea

articles/iot-operations/connect-to-cloud/howto-configure-mqtt-endpoint.md

@@ -580,7 +580,7 @@ Many MQTT brokers, like Event Grid, support X.509 authentication. Data flows can
 The certificate and private key must be in PEM format and not password protected.
 
 > [!TIP]
-> PEM format is a common format for certificates and keys. Certificates and keys in PEM format are base64-encoded ASCII files with a headers that look like `-----BEGIN CERTIFICATE-----` and `-----BEGIN EC PRIVATE KEY----`
+> PEM format is a common format for certificates and keys. Certificates and keys in PEM format are base64-encoded ASCII files with headers that look like `-----BEGIN CERTIFICATE-----` and `-----BEGIN EC PRIVATE KEY----`
 > 
 > If you have a certificate in another format, you can convert it to PEM format using OpenSSL. To learn more, see [How to convert a certificate into the appropriate format](https://knowledge.digicert.com/solution/how-to-convert-a-certificate-into-the-appropriate-format).
 
@@ -601,7 +601,7 @@ Before configuring the data flow endpoint, create a secret with the certificate
 > To use the operations experience portal to manage secrets, Azure IoT Operations must first be enabled with secure settings by configuring an Azure Key Vault and enabling workload identities. To learn more, see [Enable secure settings in Azure IoT Operations deployment](../deploy-iot-ops/howto-enable-secure-settings.md).
 
 > [!IMPORTANT]
-> The operations experience portal currently has a known issue where creating a X.509 secret results in a secret with incorrectly encoded data. To learn more and the workaround, see [known issues](../troubleshoot/known-issues.md).
+> The operations experience portal currently has a known issue where creating an X.509 secret results in a secret with incorrectly encoded data. To learn more and the workaround, see [known issues](../troubleshoot/known-issues.md).
 
 In the operations experience data flow endpoint settings page, select the **Basic** tab then choose **Authentication method** > **X509 certificate**.