Add note about ignoring mount errors

Author: genlin

support/azure/virtual-machines/linux/chroot-environment-linux.md

@@ -67,6 +67,7 @@ This article describes how to troubleshoot the chroot environment in the rescue
       ```
       > [!NOTE]
       > On newer Ubuntu images, there is only one partition for `/boot`. If you are recovering an older Ubuntu image, you can ignore errors when mounting `/dev/sdc16` to `/rescue/boot`, as long as there are files in `/rescue/boot` after completing these steps.
+      >
       > If an error occurs during mounting, it will be safe to ignore the error that occurs when unmounting `/rescue/boot` in the following step.
 
    1. Troubleshoot the chroot environment.