use xargs and add usage example

README.md

@@ -3,7 +3,38 @@
 
 # Build Container Installer Action
 
-This action is used to generate an ISO for installing an OSTree stored in a container image. This utilizes the anaconda command `ostreecontainer`, which also support bootc.
+This action is used to generate an ISO for installing an OSTree stored in a container image. This utilizes the anaconda command `ostreecontainer`, which also supports bootc.
+
+## Usage
+
+This action is designed to be called from a GitHub workflow using the following format
+
+```yaml
+- name: Build ISO
+  uses: jasonn3/build-container-installer@main
+  id: build
+  with:
+    arch: ${{ env.ARCH}}
+    image_name: ${{ env.IMAGE_NAME}}
+    image_repo: ${{ env.IMAGE_REPO}}
+    image_tag: ${{ env.IMAGE_TAG }}
+    version: ${{ env.VERSION }}
+    variant: ${{ env.VARIANT }}
+    iso_name: ${{ env.IMAGE_NAME }}-${{ env.IMAGE_TAG }}-${{ env.VERSION }}.iso
+
+# This example is for uploading your ISO as a Github artifact. You can do something similar using any cloud storage, so long as you copy the output
+- name: Upload ISO as artifact
+  id: upload
+  uses: actions/upload-artifact@v4
+  with:
+    name: ${{ steps.build.outputs.iso_name }}
+    path: |
+      ${{ steps.build.outputs.iso_path }}
+      ${{ steps.build.outputs.iso_path }}-CHECKSUM
+    if-no-files-found: error
+    retention-days: 0
+    compression-level: 0
+```
 
 **See the [Wiki](https://github.com/JasonN3/build-container-installer/wiki) for development and usage information.**