add installation details

Signed-off-by: Yves Brissaud <[email protected]>

Author: eunomie

README.md

@@ -24,3 +24,34 @@
 ```
 
 See the [Docker RunX reference](/docs/reference/runx.md) for more information.
+
+## CLI Plugin Installation
+
+### Manual Installation
+
+To install it manually:
+
+- Download the `docker-runx` binary corresponding to your platform from the [latest](https://github.com/eunomie/docker-runx/releases/latest) or [other](https://github.com/eunomie/docker-runx/releases) releases.
+- Rename it as
+    - `docker-runx` on _Linux_ and _macOS_
+    - `docker-runx.exe` on _Windows_
+- Copy the binary to the `runx` directory (you might need to create it)
+    - `$HOME/.docker/runx` on _Linux_ and _macOS_
+    - `%USERPROFILE%\.docker\runx` on _Windows_
+- Make it executable on _Linux_ and _macOS_
+    - `chmod +x $HOME/.docker/runx/docker-runx`
+- Authorize the binary to be executable on _macOS_
+    - `xattr -d com.apple.quarantine $HOME/.docker/runx/docker-runx`
+- Add the `runx` directory to your `.docker/config.json` as a plugin directory
+    - `$HOME/.docker/config.json` on _Linux_ and _macOS_
+    - `%USERPROFILE%\.docker\config.json` on _Windows_
+    - Add the `cliPluginsExtraDirs` property to the `config.json` file
+```
+{
+	...
+	"cliPluginsExtraDirs": [
+		"<full path to the .docker/runx folder>"
+	],
+	...
+}
+```