write v2 spec; all tox passing

Author: alimanfoo

docs/spec.rst

@@ -1,7 +1,10 @@
+.. _spec:
+
 Specifications
 ==============
 
 .. toctree::
     :maxdepth: 3
 
     spec/v1
+    spec/v2

docs/spec/v1.rst

@@ -10,6 +10,11 @@ NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
 interpreted as described in `RFC 2119
 <https://www.ietf.org/rfc/rfc2119.txt>`_.
 
+Status
+------
+
+This specification is deprecated. See :ref:`spec` for the latest version.
+
 Storage
 -------