Fix markdownlint, add Discourse page

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

Dockerfile-pdf-build

@@ -0,0 +1,37 @@
+ARG FROM_SOURCE=squidfunk/mkdocs-material
+FROM ${FROM_SOURCE}
+
+RUN apk add --no-cache py3-pip py3-pillow py3-cffi py3-brotli gcc musl-dev python3-dev pango build-base libffi-dev jpeg-dev libxslt-dev
+
+RUN pip install \
+        beautifulsoup4==4.9.3 \
+        mkdocs-autolinks-plugin \
+        mkdocs-htmlproofer-plugin \
+	mkdocs-git-revision-date-localized-plugin \
+        mkdocs-macros-plugin \
+        mkdocs-git-committers-plugin-2 \
+        mkdocs-meta-descriptions-plugin \
+        mkdocs-with-pdf \
+        mkdocs-extra-sass-plugin \
+        qrcode \
+        livereload
+
+# Theoretically this could add support for headless chrome
+RUN apk add --no-cache \
+      chromium \
+      nss \
+      freetype \
+      harfbuzz \
+      ca-certificates \
+      ttf-freefont \
+      nodejs \
+      yarn ttf-ubuntu-font-family dbus yarn
+
+
+RUN   git config --global --add safe.directory /docs
+
+ # Additional font 
+#  COPY fonts /usr/share/fonts/Additional 
+ RUN apk --update --upgrade --no-cache add fontconfig ttf-freefont font-noto terminus-font \ 
+     && fc-cache -f \ 
+     && fc-list | sort