GitHub ActionsでDocker Hubへのpushを行うように (#7782)

* Create docker.yml

* Update .github/workflows/docker.yml

Co-authored-by: tamaina <tamaina@hotmail.co.jp>

* add workflow_dispatch

* Multi-platform image

* Revert "Multi-platform image"

This reverts commit e5bac6632909a5020b0708227ebe248b443c2c2b.

Co-authored-by: tamaina <tamaina@hotmail.co.jp>

.github/workflows/docker.yml

+name: Publish Docker image
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+
+jobs:
+  push_to_registry:
+    name: Push Docker image to Docker Hub
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v2
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: misskey/misskey
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Build and Push to Docker Hub
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}