doc: add runbook for 'Mithril client multi-platform test'

docs/runbook/README.md

@@ -20,4 +20,5 @@ This page gathers the available guides to operate a Mithril network.
 | **Create test Docker distribution**       | [test-docker-distribution](./test-docker-distribution/README.md)       | Create a custom test Docker distribution.                                 |
 | **Deploy a test network manually**        | [test-deploy-network](./test-deploy-network/README.md)                 | Manually deploy a test distribution to a test Mithril network.            |
 | **Publish crates to crates.io manually**  | [manual-publish-crates](./manual-publish-crates/README.md)             | Manually publish Rust crates to crates.io.                                |
-| **Publish packages to npm manually**      | [manual-publish-npm](./manual-publish-npm/README.md)                   | Manually publish packages to npm registry.                                |
+| **Publish packages to npm manually**      | [manual-publish-npm](./manual-publish-npm/README.md)                   | Manually publish packages to npm registry.                                |
+| **Client multi-platform test**            | [test-client-multiplatform](./test-client-multiplatform/README.md)     | Run multi-platform client CLI binaries, docker and WASM package tests.    |

docs/runbook/test-client-multiplatform/README.md

@@ -0,0 +1,35 @@
+# Run Mithril client multi-platform test
+
+## Introduction
+
+You can manually run this workflow if you want to test the Mithril client features in the following contexts:
+- Mithril client binaries on multi-platform (Ubuntu, MacOS and Windows)
+- Mithril client docker image
+- Mithril client WASM package with headless browsers (Chrome and Firefox)
+
+## Run the associated 'Mithril Client multi-platform test' GitHub Actions workflow
+
+Go to the page of the workflow with your browser: [Mithril Client multi-platform test](https://github.com/input-output-hk/mithril/actions/workflows/test-client.yml)
+
+Then, click on the **Run workflow** button:
+
+![Run workflow button](./img/run-workflow-button.png)
+
+Then fill the form to manually run the workflow:
+
+![Run workflow form](./img/run-workflow-form-png)
+
+> [!WARNING]
+> - The **Mithril image id** of the distribution to deploy must be published on the [package registry](https://github.com/orgs/input-output-hk/packages?repo_name=mithril)
+
+> [!IMPORTANT]
+> If you want to run the tests with an aggregator that has the signing capability for Cardano transactions, you will also need to provide a list of [Cardano transactions hashes](https://sancho.cexplorer.io/tx) separated by commas.
+>
+> The aggregator capabilities are available at the root route of the aggregator `/`:
+> - [Capabilities for testing-preview aggregator](https://aggregator.testing-preview.api.mithril.network/aggregator)
+> - [Capabilities for testing-sanchonet aggregator](https://aggregator.testing-sanchonet.api.mithril.network/aggregator)
+
+
+The result should look like this in the GitHub Actions:
+
+![Run workflow result](./img/run-workflow-result.png)