Delete .github directory

.github/workflows/docker-image.yml

@@ -1,20 +0,0 @@
-name: Docker Image CI
-
-on:
-  push:
-    branches: [ main ]
-  pull_request:
-    branches: [ main ]
-
-jobs:
-
-  build:
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Build the Docker image
-      run: docker buildx build . --file Dockerfile --push \
-            --tag hongwenjun/nginx-php:$(date +%s) \
-            --platform=linux/arm,linux/arm64,linux/amd64