feat: add auto docker build. fix yaml extension

Signed-off-by: tvories <taylor@tmtech.me>

.github/workflows/docker-build.yml

@@ -0,0 +1,71 @@
+---
+
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [master]
+    tags:
+      - 'v*.*.*'
+      - 'v*'
+    # Only build when files in these directories have been changed
+    paths:
+      - client/**
+      - server/**
+  pull_request:
+    branches: [master]
+    # Only build when files in these directories have been changed
+    paths:
+      - client/**
+      - server/**
+  release:
+    types: [published, edited]
+  # Allows you to run workflow manually from Actions tab
+  workflow_dispatch:
+
+jobs:
+  build:
+    if: "!contains(github.event.head_commit.message, 'skip ci')"
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Check out
+        uses: actions/checkout@v2
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: advplyr/audiobookshelf,ghcr.io/${{ github.repository_owner }}/audiobookshelf
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+
+      - name: Setup QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to Dockerhub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+      
+      - name: Login to ghcr
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GHCR_PASSWORD }}
+
+      - name: Build image
+        uses: docker/build-push-action@v2
+        with:
+          tags: ${{ steps.meta.outputs.tags }}
+          context: .
+          platforms: linux/amd64,linux/arm64,linux/arm/v7
+          push: true