Update to use opengraph-image-gen

Dockerfile

@@ -1,31 +1,15 @@
-FROM golang:1.14-alpine as go-builder
-
-ENV GO111MODULE=on
-WORKDIR /app
-
-ADD social-image-gen .
-RUN GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -ldflags="-w -s" -o social-image-gen main.go
-
 FROM debian:buster AS builder
-
 RUN apt-get -qq update \
 	&& DEBIAN_FRONTEND=noninteractive apt-get -qq install -y --no-install-recommends libstdc++6 python-pygments git ca-certificates asciidoc curl \
 	&& rm -rf /var/lib/apt/lists/*
-
 ENV HUGO_VERSION 0.74.3
 ENV HUGO_BINARY hugo_extended_${HUGO_VERSION}_Linux-64bit.deb
 RUN curl -sL -o /tmp/hugo.deb \
     https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/${HUGO_BINARY} && \
     dpkg -i /tmp/hugo.deb && \
     rm /tmp/hugo.deb
-
-COPY --from=go-builder /app/social-image-gen /social-image-gen
-
 WORKDIR /app
 ADD . .
-
-ADD ./social-image-gen/fonts/ /fonts
-RUN /social-image-gen --mode posts
 RUN hugo -d /usr/share/nginx/html/
 
 FROM nginx:latest