readme changed

README.md

@@ -1,4 +1,23 @@
-Docker Compose + Github Actions + Layers Cache
+Docker Compose + GitHub Actions + Layers Cache
 ===
 
-Example project.
+Decrease build time of docker compose inside GitHub Actions using layers cache.
+
+2x faster builds:
+
+![Image of Build time](./.github/build_time.png)
+
+## Description
+
+* `.github/workflows/not-cached.yml` uses `./docker-compose.ci.not-cached.yml`
+* `.github/workflows/cached.yml` uses `./docker-compose.yml`. Caching achieved by:
+  * ENV variables `DOCKER_BUILDKIT` and `COMPOSE_DOCKER_CLI_BUILD`
+  * docker/setup-buildx-action
+  * --build-arg BUILDKIT_INLINE_CACHE=1
+  * `cache_from` inside docker-compose file:
+    ```yml
+    build:
+      context: ./app1
+      cache_from:
+      - ghcr.io/cyanofresh/docker-compose-ga-cache-example_app1
+    ```