feat: add Dockerfile and CI workflow for image build

.gitea/bunPipeline/Dockerfile

@@ -0,0 +1,18 @@
+from imbios/bun-node
+
+
+jobs:
+  build:
+    name: Build and push image
+    runs-on: ubuntu-latest
+    container: catthehacker/ubuntu:act-latest
+
+    steps:
+    - name: Build Docker image
+      uses: https://git.kjan.de/actions/docker-build@v1
+      with:
+        name: node-npm      
+        REGISTRY_USERNAME: ${{ secrets.REGISTRY_USERNAME }}
+        REGISTRY_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
+        DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+        DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}

.gitea/workflows/bun-image.yml

@@ -0,0 +1,38 @@
+name: Build Docker Image
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - package.json
+      - bun.lockb
+  pull_request:
+    branches:
+      - main
+    paths:
+      - package.json
+      - bun.lockb
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .gitea/bunPipeline
+          file: .gitea/bunPipeline/Dockerfile
+          push: true
+          tags: git.simonis.lol/projects/bun-casino:latest # Change this to your repo
+          cache-from: type=registry,ref=git.simonis.lol/projects/bun-casino:latest
+          cache-to: type=inline