update README

Signed-off-by: Jun Kimura <[email protected]>

README.md

@@ -3,10 +3,99 @@
 ![Test](https://github.com/hyperledger-labs/yui-relayer/workflows/Test/badge.svg)
 [![GoDoc](https://godoc.org/github.com/hyperledger-labs/yui-relayer?status.svg)](https://pkg.go.dev/github.com/hyperledger-labs/yui-relayer?tab=doc)
 
-A relayer implementation supports packet relays between various blockchains.
+An [IBC](https://github.com/cosmos/ibc) [relayer](https://github.com/cosmos/ibc/tree/main/spec/relayer/ics-018-relayer-algorithms) implementation supports heterogeneous blockchains.
 
-Currently supports:
-- Cosmos/Tendermint([ibc-go](https://github.com/cosmos/ibc-go))
+## Supported chains
+
+- Cosmos/Tendermint(with [ibc-go](https://github.com/cosmos/ibc-go))
   - This implementation is a fork of [cosmos/relayer](https://github.com/cosmos/relayer)
-- Hyperledger Fabric([fabric-ibc](https://github.com/hyperledger-labs/yui-fabric-ibc))
-- Corda([corda-ibc](https://github.com/hyperledger-labs/yui-corda-ibc))
+- EVM chains(with [ibc-solidity](https://github.com/hyperledger-labs/yui-ibc-solidity))
+- Hyperledger Fabric(with [fabric-ibc](https://github.com/hyperledger-labs/yui-fabric-ibc))
+- Corda(with [corda-ibc](https://github.com/hyperledger-labs/yui-corda-ibc))
+
+You can find a list of each supported combination of chains and examples of E2E testing with Relayer here: https://github.com/datachainlab/yui-relayer-build
+
+## Compatibility with IBC
+
+Relayer uses "vX.Y.Z" as its version format. "v0.Y.Z" will be used until Relayer's core and module interface is stable.
+
+In addition, "Y" corresponds to the specific major version of ibc-go (i.e., "X"). The following table shows the Relayer version and its corresponding ibc-go version.
+
+| Relayer | ibc-go       |
+|---------|--------------|
+| v0.2.0  | v1.0.0-beta1 |
+
+
+## Glossary
+
+- **Chain**: supports sending a transaction to the chain and querying its state
+- **Prover**: generates or query a proof of a target chain's state. This proof is verified by on-chain Light Client deployed on the counterparty chain.
+- **ProvableChain**: consists of a Chain and a Prover.
+- **Path**: is a path of two ProvableChains that relay packets to each other.
+- **ChainConfig**: is a configuration to generate a Chain. It requires implementing `Build` method to build the Chain.
+- **ProverConfig**: is a configuration to generate a Prover. It also requires implementing `Build` method to build the Prover.
+
+## How to support a new chain
+
+Relayer can support additional chains you want without forking the repository.
+
+Relayer can be used as a library to configure your relayer that supports any chain or Light Client. You must provide a module that implements [Module interface](./config/module.go). The following is the implementation of the tendermint module:
+
+```go
+import (
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
+	"github.com/hyperledger-labs/yui-relayer/chains/tendermint"
+	"github.com/hyperledger-labs/yui-relayer/chains/tendermint/cmd"
+	"github.com/hyperledger-labs/yui-relayer/config"
+	"github.com/spf13/cobra"
+)
+
+type Module struct{}
+
+var _ config.ModuleI = (*Module)(nil)
+
+// Name returns the name of the module
+func (Module) Name() string {
+	return "tendermint"
+}
+
+// RegisterInterfaces register the module interfaces to protobuf Any.
+func (Module) RegisterInterfaces(registry codectypes.InterfaceRegistry) {
+	registry.RegisterImplementations(
+		(*core.ChainConfigI)(nil),
+		&ChainConfig{},
+	)
+	registry.RegisterImplementations(
+		(*core.ProverConfigI)(nil),
+		&ProverConfig{},
+	)
+}
+
+// GetCmd returns the command
+func (Module) GetCmd(ctx *config.Context) *cobra.Command {
+	return cmd.TendermintCmd(ctx.Codec, ctx)
+}
+
+```
+
+A module can be used through a relayer configuration file by registering a Config implementation for a target Chain or Prover in `RegisterInterfaces` method.
+
+You can use it by specifying the package name of the proto definition corresponding to the Config in the "@type" field of the config file, as shown below. Then, the relayer creates an instance of the corresponding Chain or Prover using the Config at runtime.
+
+```json
+{
+  "chain": {
+    "@type": "/relayer.chains.tendermint.config.ChainConfig",
+    "key": "testkey",
+    "chain_id": "ibc0",
+    "rpc_addr": "http://localhost:26657",
+    "account_prefix": "cosmos",
+    "gas_adjustment": 1.5,
+    "gas_prices": "0.025stake"
+  },
+  "prover": {
+    "@type": "/relayer.chains.tendermint.config.ProverConfig",
+    "trusting_period": "336h"
+  }
+}
+```