ecrplugin readme

Author: ikhandamirov

cmds/ecrplugin/README.md

@@ -0,0 +1,28 @@
+## AWS ECR Repository Creation Plugin
+
+The goal of the plugin is to assure the existence of required AWS ECR repositories, when used with OCM CLI.
+
+## Usage
+
+1. Install the latest version of the plugin with OCM CLI:
+    ```console
+    ocm install plugin ghcr.io/open-component-model/ocm//ocm.software/plugins/ecrplugin
+    ```
+
+2. Configure an `ocmconfig`with credentials:
+    ```yaml
+    configurations:
+      - type: credentials.config.ocm.software
+        consumers:
+          - identity:
+              type: AWS
+            credentials:
+              - type: Credentials
+                properties:
+                  awsAccessKeyID: "xxx"
+                  awsSecretAccessKey: "yyy"
+    ```
+
+3. Do `ocm transfer`. The plugin will be called automatically and make sure the target repository exists,
+if the URL of the target repository fits to this pattern:
+https://github.com/open-component-model/ocm/blob/main/cmds/ecrplugin/actions/action.go#L110