Fix: Usage examples in README.md

README.md

@@ -10,7 +10,54 @@ That is, when you enable this action, the action will fail when a `composer.json
 
 ## Usage
 
-Define a workflow in `.github/workflows/ci.yml` (or add a job if you alread have defined workflows) like this:
+Define a workflow in `.github/workflows/ci.yml` (or add a job if you already have defined workflows).
+
+:bulb: Read more about [Configuring a workflow](https://help.github.com/en/articles/configuring-a-workflow).
+
+There are two ways of using this action:
+
+* using the pre-built Docker image (faster)
+* letting GitHub build the Docker image for you (slower)
+
+### Pre-built Docker image
+
+As an integration with [Travis CI](https://travis-ci.com) automatically builds and pushes a Docker image when a new tag is created in this repository, the recommended way to use this action is to reference the pre-built Docker image directly:
+
+```yaml
+name: CI
+
+on: push
+
+jobs:
+  composer-normalize:
+    name: composer-normalize
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: composer-normalize-action
+        uses: docker://localheinz/composer-normalize-action:latest
+```
+
+Instead of using the latest pre-built Docker image, you can also specify a Docker image tag (which corresponds to the tags available here on GitHub):
+
+```yaml
+name: CI
+
+on: push
+
+jobs:
+  composer-normalize:
+    name: composer-normalize
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: composer-normalize-action
+        uses: docker://localheinz/composer-normalize-action:0.4.2
+```
+
+### GitHub Repository
+
+If you prefer to have GitHub to build the image for you, you can specify the repository instead:
 
 ```yaml
 name: CI
@@ -24,10 +71,10 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: composer-normalize-action
-        uses: localheinz/composer-normalize-action
+        uses: localheinz/composer-normalize-action@master
 ```
 
-You can also use a specific tag, for example, `x.y.z` (otherwise, `latest` will be used).
+Instead of using the `master` branch, you can also specify a tag:
 
 ```yaml
 name: CI
@@ -41,7 +88,7 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: composer-normalize-action
-        uses: localheinz/composer-normalize-action@0.4.1
+        uses: localheinz/composer-normalize-action@0.4.2
 ```
 
 ### Environment Variables
@@ -60,14 +107,18 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: composer-normalize-action
-        uses: localheinz/composer-normalize-action
+        uses: docker://localheinz/composer-normalize-action:0.4.2
         env:
           COMPOSER_NORMALIZE_VERSION: '^1.3.0'
 ```
 
-The value can be a range (for example, `^1.3.0`) or an exact version (for example, `1.2.0`).
+This value will be passed to [`entrypoint.sh`](entrypoint.sh) where it will be passed to
+
+```
+$ composer global require localheinz/composer-normalize:$COMPOSER_NORMALIZE_VERSION
+```
 
-:bulb: Also see [Automating your workflow with GitHub Actions](https://help.github.com/en/categories/automating-your-workflow-with-github-actions)
+so it can be any value that is understood by [`composer`](https://getcomposer.org/doc/articles/versions.md).
 
 ## Examples
 
@@ -77,18 +128,6 @@ To see this action in action, take a look at the following checks:
 * https://github.com/localheinz/composer-normalize-action-example/pull/2/checks
 * https://github.com/localheinz/composer-normalize-action-example/pull/3/checks
 
-## Docker
-
-A docker image is automatically built and pushed to Docker Hub, see [`localheinz/composer-normalize-action`](https://cloud.docker.com/repository/docker/localheinz/composer-normalize-action).
-
-You can execute the image by running
-
-```
-$ docker run --interactive --rm --tty --workdir=/app --volume ${PWD}:/app localheinz/composer-normalize-action
-```
-
-:bulb: Also see [Docker Docs: Docker run reference](https://docs.docker.com/engine/reference/run/).
-
 ## Changelog
 
 Please have a look at [`CHANGELOG.md`](CHANGELOG.md).