Added IBC MVP spec

docs/spec/ibc/ibc.md

@@ -0,0 +1,36 @@
+# IBC Spec
+
+*This is a living document and should be edited as the IBC spec and implementation change*
+
+## MVP1
+
+The initial implementation of IBC will include just enough for simple coin transfers between chains, with safety features such as ACK messages being added later.
+
+### IBC Module
+
+```golang
+type IBCOutMsg struct {
+  IBCTransfer
+}
+
+type IBCInMsg struct {
+  IBCTransfer
+}
+
+type IBCTransfer struct {
+  Destination sdk.Address
+  Coins       sdk.Coins
+}
+```
+
+## Relayer
+
+**Packets**
+- Connect to 2 Tendermint RPC endpoints
+- Query for IBC outgoing `IBCOutMsg` queue (can poll on a certain time interval, or check after each new block, etc)
+- For any new `IBCOutMsg`, build `IBCInMsg` and post to destination chain
+
+## CLI
+
+- Load relay process
+- Execute `IBCOutMsg`