feat: Add support math notation in kramdown-rfc

This change adds utftex and tex2svg.
Fixes #352

Dockerfile

@@ -3,6 +3,7 @@ LABEL maintainer="Kesara Rathnayake <kesara@staff.ietf.org>"
 
 ENV DEBIAN_FRONTEND noninteractive
 ENV PATH=$PATH:./node_modules/.bin
+ENV LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH
 # Disable local file read for kramdown-rfc
 ENV KRAMDOWN_SAFE=1
 
@@ -12,22 +13,26 @@ SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 RUN apt-get update && \
     apt-get install -y \
+        autoconf \
         software-properties-common \
         gcc \
         wget \
         ruby \
         python3.10 \
         python3-pip \
+        pkg-config \
+        libtool \
         libpango-1.0-0 \
         wdiff \
         rfcdiff \
         npm \
         gawk \
         bison \
         flex && \
-     rm -rf /var/lib/apt/lists/* /var/log/dpkg.log && \
-     apt-get autoremove -y && \
-     apt-get clean -y
+    rm -rf /var/lib/apt/lists/* /var/log/dpkg.log && \
+    apt-get autoremove -y && \
+    apt-get clean -y && \
+    ldconfig
 
 # Install required fonts
 RUN mkdir -p ~/.fonts/opentype && \
@@ -63,6 +68,16 @@ RUN arch=$(arch | sed s/aarch64/arm64/ | sed s/x86_64/amd64/) && \
     tar zxf mmark_*.tgz -C /bin/ && \
     rm mmark_*.tgz
 
+# Install utftex
+RUN export UTFTEX=libtexprintf-1.25 && \
+    wget -q https://github.com/bartp5/libtexprintf/archive/refs/tags/v1.25.zip && \
+    unzip -q v1.25.zip -d /tmp/ && \
+    cd /tmp/$UTFTEX && \
+    ./autogen.sh && \
+    ./configure && \
+    make install && \
+    rm -r /tmp/$UTFTEX /usr/src/app/v1.25.zip
+
 COPY Gemfile Gemfile.lock LICENSE README.md api.yml constraints.txt package-lock.json package.json requirements.txt .
 COPY at ./at