Update example YAML to use arrays for plugins

README.md

@@ -3,8 +3,6 @@ Shell script linter plugin for Buildkite
 
 [![Build status](https://badge.buildkite.com/c00862681e75d87436590fe047fab7ef179142ebdacd3c40c0.svg?branch=master)](https://buildkite.com/operable/shellcheck-buildkite-plugin)
 
-**NOTE: Plugins only work with the as yet unlreleased 3.0 version of the Buildkite Agent!**
-
 **NOTE: This plugin is a work-in-progress. We use it internally at Operable to test our bundles. However, it may still blow up your systems; use at your own discretion!**
 
 This plugin allows you to lint your shell scripts using [shellcheck](https://github.com/koalaman/shellcheck). It is implememnted in terms of the Docker image for `shellcheck`, so it must be run on a build agent that has access to `docker`.
@@ -38,22 +36,22 @@ Codes for the warnings can be found in the [shellcheck wiki](https://github.com/
 - steps
   - label: Simple linting
     plugins:
-      operable/shellcheck:
-        script: my_script.sh
+      - operable/shellcheck:
+          script: my_script.sh
 
   - label: Lint multiple scripts
     plugins:
-      operable/shellcheck:
-        script:
-          - my_script.sh
-          - my_other_script.sh
-          - yet_another_script.sh
+      - operable/shellcheck:
+          script:
+            - my_script.sh
+            - my_other_script.sh
+            - yet_another_script.sh
 
   - label: Exclude some warnings
     plugins:
-      operable/shellcheck:
-        script: my_script.sh
-        opts: --exclude=1000
+      - operable/shellcheck:
+          script: my_script.sh
+          opts: --exclude=1000
 ```
 
 Also see this plugin's [pipeline configuration](.buildkite/pipeline.sh) for other examples.