Add caching for Docker image builds

Author: dvlaskin

.github/workflows/docker-image.yml

@@ -58,6 +58,8 @@ jobs:
           tags: |
             ${{ secrets.DOCKERHUB_USERNAME }}/${{ env.APP_NAME }}:${{ steps.vars.outputs.version }}
             ${{ secrets.DOCKERHUB_USERNAME }}/${{ env.APP_NAME }}:latest
+          cache-from: type=registry,ref=${{ secrets.DOCKERHUB_USERNAME }}/${{ env.APP_NAME }}:buildcache
+          cache-to: type=registry,ref=${{ secrets.DOCKERHUB_USERNAME }}/${{ env.APP_NAME }}:buildcache,mode=max
           build-args: |
             DOTNET_CLI_TELEMETRY_OPTOUT=1
             DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1