docs/spec: update readme

docs/spec/README.md

@@ -1,20 +1,27 @@
 # Cosmos Hub Spec
 
-This directory contains specifications for the application level components of 
-the Cosmos Hub.
+This directory contains specifications for the state transition machine of the
+Cosmos Hub. 
 
-NOTE: the specifications are not yet complete and very much a work in progress.
+The Cosmos Hub holds all of its state in a Merkle store. Updates to
+the store may be made during transactions and at the beginning and end of every
+block.
+
+While the first implementation of the Cosmos Hub is built using the Cosmos-SDK,
+these specifications aim to be independent of any implementation details. That
+said, they provide a detailed resource for understanding the Cosmos-SDK.
 
 - [Store](store) - The core Merkle store that holds the state.
 - [Auth](auth) - The structure and authentication of accounts and transactions.
 - [Bank](bank) - Sending tokens.
 - [Governance](governance) - Proposals and voting.
-- [IBC](ibc) - Inter-Blockchain Communication (IBC) protocol.
 - [Staking](staking) - Proof-of-stake bonding, delegation, etc.
 - [Slashing](slashing) - Validator punishment mechanisms.
 - [Provisioning](provisioning) - Fee distribution, and atom provision distribution 
+- [IBC](ibc) - Inter-Blockchain Communication (IBC) protocol.
 - [Other](other) - Other components of the Cosmos Hub, including the reserve 
   pool, All in Bits vesting, etc.
 
-The [specification for Tendermint](https://github.com/tendermint/tendermint/tree/develop/docs/specification/new-spec),
-i.e. the underlying blockchain, can be found elsewhere.
+For details on the underlying blockchain and p2p protocols, see
+the [Tendermint specification](https://github.com/tendermint/tendermint/tree/develop/docs/spec).
+