Update README.md and docs

Author: mcalhoun

README.md

@@ -102,6 +102,7 @@ raw list of affected stacks as an output as well as a matrix that can be used fu
 | Name | Description | Default | Required |
 |------|-------------|---------|----------|
 | atmos-config-path | The path to the atmos.yaml file | atmos.yaml | false |
+| atmos-include-spacelift-admin-stacks | Whether to include the Spacelift admin stacks of affected stacks in the output | true | false |
 | atmos-version | The version of atmos to install if install-atmos is true | latest | false |
 | default-branch | The default branch to use for the base ref. | ${{ github.event.repository.default\_branch }} | false |
 | head-ref | The head ref to checkout. If not provided, the head default branch is used. | N/A | false |

docs/github-action.md

@@ -5,6 +5,7 @@
 | Name | Description | Default | Required |
 |------|-------------|---------|----------|
 | atmos-config-path | The path to the atmos.yaml file | atmos.yaml | false |
+| atmos-include-spacelift-admin-stacks | Whether to include the Spacelift admin stacks of affected stacks in the output | true | false |
 | atmos-version | The version of atmos to install if install-atmos is true | latest | false |
 | default-branch | The default branch to use for the base ref. | ${{ github.event.repository.default\_branch }} | false |
 | head-ref | The head ref to checkout. If not provided, the head default branch is used. | N/A | false |