publish image on release (#174)

* add a Dockerfile, use an action to build and publish it, and update readme to reflect

.github/workflows/publish.yml

@@ -0,0 +1,42 @@
+name: Create and publish a Docker image
+
+on:
+  release:
+    types: [published]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/[email protected]
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/[email protected]
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/[email protected]
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

.gitignore

@@ -1,2 +1,2 @@
 etc*
-*\.yml
+compose.yml

Dockerfile

@@ -0,0 +1,2 @@
+FROM pihole/pihole:latest
+RUN curl -sSLN https://github.com/arevindh/pi-hole/raw/master/advanced/Scripts/speedtestmod/mod.sh | sudo bash

README.md

@@ -35,18 +35,27 @@ Pull requests and suggestions are welcome!
 
 Please use our Mod Script to install the latest version of the Mod; it automates the process of swapping Pi-hole's repos to our modded ones and ensures this is done efficiently. To see available options, please look at the [wiki](https://github.com/arevindh/pihole-speedtest/wiki). For information about running Pi-hole in Docker, including a Compose example, please refer to the official [repo](https://github.com/pi-hole/docker-pi-hole/) and [docs](https://docs.pi-hole.net/).
 
-> **Docker Note**
-> You'll need to run the script inside every new container if you're not using Compose.
-
 ### Via the Shell
 
-You can just pipe to bash!
+You can just pipe to bash:
 
     curl -sSLN https://github.com/arevindh/pi-hole/raw/master/advanced/Scripts/speedtestmod/mod.sh | sudo bash
 
-### Docker Compose
+### With Docker
+
+Simply change the image you're using to our modded one:
+
+    ghcr.io/ipitio/pihole-speedtest:latest
+
+#### Compose
+
+Choose one of the following options:
+
+* Change the `image: ...` line to point to our image,
+* Replace it with the following and rebuild without cache, or
+* Run the Mod Script manually inside every new container.
 
-Replace `image: pihole/pihole:latest` with the following in your `compose.yml`, then rebuild without cache.
+The last option is not recommended.
 
     build:
         dockerfile_inline: |