docs: kvm: review-checklist.txt: rename to ReST

This file is already in ReST compatible format.
So, rename it and add to the kvm's index.rst.

While here, use the standard conversion for document titles.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/index.rst

@@ -21,6 +21,8 @@ KVM
    timekeeping
    vcpu-requests
 
+   review-checklist
+
    arm/index
 
    devices/index

Documentation/virt/kvm/review-checklist.txt → Documentation/virt/kvm/review-checklist.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+================================
 Review checklist for kvm patches
 ================================