make: add CI to build dockerfile (#12)

* make: add CI to build dockerfile

* docs: add docker step in the readme

.github/workflows/build.yaml

@@ -0,0 +1,29 @@
+on:
+  push:
+    branches:
+      - master
+name: Build the docker container
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build and push
+        run: |
+          docker buildx build -f Dockerfile . --tag ghcr.io/${{ github.actor }}/arma-3-artillery-calculator:latest --platform linux/amd64,linux/arm64 --push

README.md

@@ -2,6 +2,19 @@
 ARES is a web service to calculate the elevation, heading, and fire mode needed to precisely hit desired targets in Bohemia Interactive's **Arma 3**. When loading the web app, you get to choose between the classic artillery computer for the **2S9 Sochor** and **M4 Scorcher**, or, you are finally able to opt for the _**redneck artillery**_ version designed for the **MAAWS Mk4 Mod 0** – _Be the real King of the Hill!_
 
 ### Get ARES
+
+#### Docker
+
+You need to have Docker or Podman installed and simply run: `docker run -p 8080:80 ghcr.io/Dreamfarer/arma-3-artillery-calculator:latest`. The interface will be accessible from `http://localhost:8080` or `http://your-server-ip:8080`
+
+Or you can build the container yourself:
+```bash
+docker build . -t ghcr.io/Dreamfarer/arma-3-artillery-calculator
+docker run -p 8080:80 ghcr.io/Dreamfarer/arma-3-artillery-calculator
+```
+
+#### Bare
+
 It is as simple as cloning this repository and double-clicking the `.html` file. However, there is yet a more convenient way: Head straight to the live version of this artillery calculator found [HERE](https://arma.openlink.bot/ares) – Free of charge and no nasty trackers nor advertisements!
 
 ### How to Use?