Add chain connector plugin readme (#9055)

* Add README

* Update doc ref link for chain-connector

* Add details to chain connector plugin README

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Co-authored-by: !shan <ishantiw.quasar@gmail.com>

framework-plugins/lisk-framework-chain-connector-plugin/README.md

@@ -0,0 +1,78 @@
+# @liskhq/lisk-framework-chain-connector-plugin
+
+@liskhq/lisk-framework-chain-connector-plugin is a plugin for creating and sending Cross-Chain-Update (CCU) Transactions.
+
+Cross-chain update transactions are the carriers of the information transmitted between chains. By posting a cross-chain update, the receiving chain gets the information required about the advancement of the sending chain. The transaction can also include cross-chain messages and thus serves as an envelope for messages from one chain to another.
+
+## Installation
+
+```sh
+$ npm install --save @liskhq/lisk-framework-chain-connector-plugin
+```
+
+## Config Options
+
+```
+{
+	receivingChainID: string,
+	receivingChainWsURL?: string,
+	receivingChainIPCPath?: string,
+	ccuFrequency: number,
+	encryptedPrivateKey: string,
+	ccuFee: string,
+	isSaveCCU: boolean,
+	maxCCUSize: number,
+	registrationHeight: number,
+	ccuSaveLimit: number
+}
+```
+
+## Parameters
+
+| Param                   | Required? | Description                                                                    |
+| ----------------------- | --------- | ------------------------------------------------------------------------------ |
+| `receivingChainID`      | **Y**     | Chain ID of the receiving chain                                                |
+| `receivingChainWsURL`   | **N**     | The WS url of a receiving node                                                 |
+| `receivingChainIPCPath` | **N**     | The IPC path of a receiving node                                               |
+| `ccuFrequency`          | **Y**     | Number of blocks after which a CCU should be created                           |
+| `encryptedPrivateKey`   | **Y**     | Encrypted privateKey of the relayer                                            |
+| `ccuFee`                | **Y**     | Fee to be paid for each CCU transaction                                        |
+| `isSaveCCU`             | **Y**     | Flag for the user to either save or send a CCU on creation. Send is by default |
+| `maxCCUSize`            | **Y**     | Maximum size of CCU to be allowed                                              |
+| `registrationHeight`    | **Y**     | Height at the time of registration on the receiving chain                      |
+| `ccuSaveLimit`          | **Y**     | Number of CCUs to save                                                         |
+
+## Usage
+
+Start your Lisk SDK with `--enable-chain-connector-plugin` flag, i.e.
+
+```sh
+    $ ./bin/run start --enable-chain-connector-plugin
+```
+
+## Documentation
+
+[Setting up a relayer node](https://lisk.com/documentation/beta/run-blockchain/setup-relayer.html#installing-the-chain-connector-plugin): Details SDK Doc for setting up node with Chain Connector Plugin.
+
+[LIP-53 # CCU Properties](https://github.com/LiskHQ/lips/blob/main/proposals/lip-0053.md#cross-chain-update-transaction-properties): Explaination of CCU Properties from LIP-53.
+
+[Interoperability Example](https://github.com/LiskHQ/lisk-sdk/tree/release/6.1.0/examples/interop): Example of Interoperability with 2 sidechains and 1 mainchain, Chain Connector Plugin enabled.
+
+## License
+
+Copyright 2016-2023 Lisk Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+[lisk core github]: https://github.com/LiskHQ/lisk
+[lisk documentation site]: https://lisk.com/documentation/lisk-sdk/v6/references/typedoc/modules/_liskhq_lisk_framework_chain_connector_plugin.html