* Update upgrade docs
Signed-off-by: Carlisia <carlisia@vmware.com>

* Update TOC
Signed-off-by: Carlisia <carlisia@vmware.com>

* The right next version is v1.6.0-beta.1
Signed-off-by: Carlisia <carlisia@vmware.com>

* Correct the listing order
Signed-off-by: Carlisia <carlisia@vmware.com>