Add focal docker file with arm support

focal-latest/Dockerfile

@@ -0,0 +1,47 @@
+FROM eclipse-temurin:11-jdk-focal
+
+SHELL ["/bin/bash", "-c"]
+
+RUN addgroup --system dtcgroup && adduser --system dtcuser --ingroup dtcgroup
+
+RUN apt-get update && apt-get upgrade -y && \
+    apt-get install -y build-essential curl wget zip unzip git bash graphviz python3 ruby-dev \
+    python3-pygments libyaml-dev ttf-dejavu
+RUN gem update --system && gem install rdoc --no-document && gem install pygments.rb
+
+
+USER dtcuser
+WORKDIR /home/dtcuser
+ENV HOME=/home/dtcuser
+
+ENV GRADLE_USER_HOME=/home/dtcuser/.gradle
+
+ARG DTC_VERSION
+RUN     git clone --branch ng https://github.com/docToolchain/docToolchain.git  && \
+        cd docToolchain && \
+        git fetch --tags && \
+        git checkout ${DTC_VERSION} && \
+        git submodule update -i && \
+        # remove .git folders
+        rm -rf `find -type d -name .git` && \
+        umask g+w && \
+        ./gradlew downloadDependencies && \
+        chmod -R o=u $GRADLE_USER_HOME && \
+        chmod -R g=u $GRADLE_USER_HOME && \
+        rm -r $GRADLE_USER_HOME/daemon && \
+        chmod -R o=u $HOME
+
+# add reveal.js
+RUN     cd /home/dtcuser/docToolchain/resources/. && \
+        ./clone.sh && \
+        cd -
+
+ENV PATH="/home/dtcuser/docToolchain/bin:${PATH}"
+
+USER dtcuser
+
+WORKDIR /project
+
+VOLUME /project
+
+ENTRYPOINT /bin/bash