move list-targets docs to its own readme

Signed-off-by: CrazyMax <[email protected]>

Author: crazy-max

.github/subaction-list-targets.png

@@ -22,9 +22,7 @@ ___
   * [outputs](#outputs)
   * [environment variables](#environment-variables)
 * [Subactions](#subactions)
-  * [`list-targets`](#list-targets)
-    * [inputs](#inputs-1)
-    * [outputs](#outputs-1)
+  * [`list-targets`](subaction/list-targets)
 * [Contributing](#contributing)
 
 ## Usage
@@ -216,76 +214,7 @@ The following outputs are available
 
 ## Subactions
 
-### `list-targets`
-
-This subaction generates a list of Bake targets that can be used in a [GitHub matrix](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix),
-so you can distribute your builds across multiple runners.
-
-```hcl
-# docker-bake.hcl
-group "validate" {
-  targets = ["lint", "doctoc"]
-}
-
-target "lint" {
-  target = "lint"
-}
-
-target "doctoc" {
-  target = "doctoc"
-}
-```
-
-```yaml
-jobs:
-  prepare:
-    runs-on: ubuntu-latest
-    outputs:
-      targets: ${{ steps.generate.outputs.targets }}
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v4
-      -
-        name: List targets
-        id: generate
-        uses: docker/bake-action/subaction/list-targets@v4
-        with:
-          target: validate
-
-  validate:
-    runs-on: ubuntu-latest
-    needs:
-      - prepare
-    strategy:
-      fail-fast: false
-      matrix:
-        target: ${{ fromJson(needs.prepare.outputs.targets) }}
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v4
-      -
-        name: Validate
-        uses: docker/bake-action@v5
-        with:
-          targets: ${{ matrix.target }}
-```
-#### inputs
-
-| Name         | Type        | Description                                                                                                                                 |
-|--------------|-------------|---------------------------------------------------------------------------------------------------------------------------------------------|
-| `workdir`    | String      | Working directory to use (defaults to `.`)                                                                                                  |
-| `files`      | List/CSV    | List of [bake definition files](https://docs.docker.com/build/customize/bake/file-definition/)                                              |
-| `target`     | String      | The target to use within the bake file                                                                                                      |
-
-#### outputs
-
-The following outputs are available
-
-| Name       | Type     | Description                |
-|------------|----------|----------------------------|
-| `targets`  | List/CSV | List of extracted targest  |
+* [`list-targets`](subaction/list-targets)
 
 ## Contributing
 

README.md

@@ -0,0 +1,84 @@
+## About
+
+This subaction generates a list of Bake targets that can be used in a [GitHub matrix](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix),
+so you can distribute your builds across multiple runners.
+
+![Screenshot](../../.github/bake-action.png)
+
+___
+
+* [Usage](#usage)
+* [Customizing](#customizing)
+  * [inputs](#inputs)
+  * [outputs](#outputs)
+
+## Usage
+
+```hcl
+# docker-bake.hcl
+group "validate" {
+  targets = ["lint", "doctoc"]
+}
+
+target "lint" {
+  target = "lint"
+}
+
+target "doctoc" {
+  target = "doctoc"
+}
+```
+
+```yaml
+jobs:
+  prepare:
+    runs-on: ubuntu-latest
+    outputs:
+      targets: ${{ steps.generate.outputs.targets }}
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v4
+      -
+        name: List targets
+        id: generate
+        uses: docker/bake-action/subaction/list-targets@v4
+        with:
+          target: validate
+
+  validate:
+    runs-on: ubuntu-latest
+    needs:
+      - prepare
+    strategy:
+      fail-fast: false
+      matrix:
+        target: ${{ fromJson(needs.prepare.outputs.targets) }}
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v4
+      -
+        name: Validate
+        uses: docker/bake-action@v5
+        with:
+          targets: ${{ matrix.target }}
+```
+
+## Customizing
+
+### inputs
+
+| Name         | Type        | Description                                                                                                                                 |
+|--------------|-------------|---------------------------------------------------------------------------------------------------------------------------------------------|
+| `workdir`    | String      | Working directory to use (defaults to `.`)                                                                                                  |
+| `files`      | List/CSV    | List of [bake definition files](https://docs.docker.com/build/customize/bake/file-definition/)                                              |
+| `target`     | String      | The target to use within the bake file                                                                                                      |
+
+### outputs
+
+The following outputs are available
+
+| Name       | Type     | Description                |
+|------------|----------|----------------------------|
+| `targets`  | List/CSV | List of extracted targest  |