Update pandoc dockerfile and latex template and fix infinite build, fix pandoc always pull and fix strikethrough (#100, #103 and #115)

build/Dockerfile

@@ -1,29 +1,10 @@
-FROM haskell:latest
+FROM pandoc/ubuntu
 
-# based on implementation by James Gregory <james@jagregory.com>
-MAINTAINER Comply <comply@strongdm.com>
-
-# install latex packages
 RUN apt-get update -y \
-  && apt-get install -y -o Acquire::Retries=10 --no-install-recommends \
-    texlive-latex-base \
-    texlive-xetex \
-    texlive-fonts-recommended \
-    latex-xcolor \
-    texlive-latex-extra \
-    fontconfig \
-    unzip \
-    lmodern
-
-# will ease up the update process
-# updating this env variable will trigger the automatic build of the Docker image
-ENV PANDOC_VERSION "2.2.1"
-
-# install pandoc
-RUN cabal update && cabal install pandoc-${PANDOC_VERSION}
+  && DEBIAN_FRONTEND=noninteractive apt-get install -y -o Acquire::Retries=10 --no-install-recommends \
+  texlive-latex-base \
+  texlive-latex-extra \
+  texlive-plain-generic \
+  lmodern
 
 WORKDIR /source
-
-ENTRYPOINT ["/root/.cabal/bin/pandoc"]
-
-CMD ["--help"]