chore: update readme

- add more detailed default readme

README.md

@@ -1,5 +1,95 @@
-# Docker Image Build: almalinux template
+# Docker Image Build: Almalinux Template
-
-[![Build Status](https://droneci.query.consul/api/badges/unkin/docker-almalinux-base/status.svg)](https://droneci.query.consul/unkin/docker-almalinux-base)
 
 This project provides a reproducible Docker image build process for `almalinux:8.10`, with custom YUM repository configurations and package installations. The build is automated using a `Makefile` and managed via CI tasks to ensure consistent and reliable Docker image builds.
+
+## Makefile Overview
+
+The `Makefile` provides several targets to automate building, tagging, and pushing Docker images. The Docker image is tagged with the current Git commit hash, the current date, and a `latest` tag for easy reference.
+
+## Makefile Targets
+
+### Build the Docker Image
+
+To build the Docker image without tags:
+
+```bash
+make build
+```
+
+This will use the `docker build` command with `--network=host` to build the image with the name `git.query.consul/unkin/almalinux8-template`.
+
+### Tag the Docker Image
+
+To tag the Docker image with the Git commit hash, the current date, and a `latest` tag:
+
+```bash
+make tag
+```
+
+This will add three tags to the image:
+- `git.query.consul/unkin/almalinux8-template:<GIT_COMMIT>`
+- `git.query.consul/unkin/almalinux8-template:<DATE_TAG>`
+- `git.query.consul/unkin/almalinux8-template:latest`
+
+### Push the Docker Image
+
+To push the tagged Docker images to the registry:
+
+```bash
+make push
+```
+
+> **Note**: The `push` command is currently commented out for safety. To enable pushing, remove the comment (`#`) from the `docker push` lines in the `push` target.
+
+### Clean Up
+
+To clean up any dangling Docker images:
+
+```bash
+make clean
+```
+
+This will remove any dangling (unused) Docker images using `docker image prune -f`.
+
+### Default Target
+
+The default target is `build`. So running:
+
+```bash
+make
+```
+
+is equivalent to running `make build`.
+
+## Development and Testing
+
+To test or develop with this `Makefile`, follow these steps:
+
+1. **Clone the repository** and navigate to the project directory:
+   ```bash
+   git clone https://git.query.consul/unkin/docker-template.git
+   cd docker-template
+   ```
+
+2. **Build the Docker image** using the `build` target:
+   ```bash
+   make build
+   ```
+
+3. **Tag the image** with the commit hash, date, and latest tag:
+   ```bash
+   make tag
+   ```
+
+4. **(Optional)** Modify the `push` target to enable pushing the image to your Docker registry:
+   Uncomment the lines in the `push` target:
+   ```makefile
+   docker push $(REGISTRY)/$(OWNER)/$(IMAGE_NAME):$(GIT_COMMIT)
+   docker push $(REGISTRY)/$(OWNER)/$(IMAGE_NAME):$(DATE_TAG)
+   docker push $(REGISTRY)/$(OWNER)/$(IMAGE_NAME):latest
+   ```
+
+5. **Test your changes** locally by running the `clean` target:
+   ```bash
+   make clean
+   ```