Update readme and remove non functional workflow

.github/workflows/docker.yaml

@@ -1,43 +0,0 @@
-name: build-docker-image
-
-on:
-  push:
-    branches:
-      - 'main'
-
-env:
-  REGISTRY: gitea.lol3r.com
-  IMAGE_NAME: ${{ github.repository }}
-
-jobs:
-  docker:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v4
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v4
-      - name: Login to Github
-        uses: docker/login-action@v4
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@v5
-        with:
-          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
-          tags: |
-            # set latest tag for master branch
-            type=raw,value=latest,enable={{is_default_branch}}
-      - name: Build and push
-        uses: docker/build-push-action@v7
-        with:
-          context: .
-          file: Dockerfile
-          push: true
-          tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}

README.md

@@ -1,2 +1,5 @@
 # Blog
 My personal blog
+
+## Build Docker image
+`docker buildx build --platform=linux/amd64 -t gitea.lol3r.com/leon/blog:latest .`