Add features dev and support policy doc
Add features dev and support policy doc

Related https://github.com/etcd-io/etcd/issues/13775

Signed-off-by: Sahdev Zala <e752d44c9d22c9ff5ec46b8ef5c7507f41d82165@us.ibm.com>

ajityagaty/etcd,ajityagaty/etcd,ajityagaty/etcd,etcd-io/etcd,etcd-io/etcd,etcd-io/etcd