update compatibility

Author: PaulAngus

source/releasenotes/compat.rst

@@ -44,13 +44,14 @@ and VMware with vSphere.
 -  CentOS 6.2+, 7.0+ with KVM
 -  Ubuntu 14.04LTS, 16.04LTS, 18.04LTS with KVM
 -  Red Hat Enterprise Linux 6.2 with KVM
--  XenServer versions 6.1, 6.2 SP1, 6.5, 7.0, 7.1, 7.2 with latest hotfixes, XCP-ng 7.4
+-  XenServer versions 6.1, 6.2 SP1, 6.5, 7.0, 7.1, 7.2 with latest hotfixes, XCP-ng 7.4, 7.6
 
    .. note:: It is now required to enable HA on the XenServer pool in order to recover from a pool-master failure. Please refer to the `XenServer documentation <http://docs.vmd.citrix.com/XenServer/6.5.0/1.0/en_gb/>`_.
 
 -  VMware versions 5.0, 5.1, 5.5, 6.0, 6.5 and 6.7
-   .. note:: There is a known issue in 6.7u1 (https://kb.vmware.com/s/article/67315) which blocks some 
-      CloudStack cloning operations. The use of linked clones is known to be effected.
+
+   .. note:: There is a known issue in 6.7u1 (https://kb.vmware.com/s/article/67315) which blocks some CloudStack cloning operations. The use of linked clones is known to be effected.
+
 -  LXC Host Containers on RHEL 7
 -  Windows Server 2012 R2 (with Hyper-V Role enabled)
 -  Hyper-V 2012 R2