More inline docs

Author: Ayaz Salikhov

base-notebook/Dockerfile

@@ -19,21 +19,26 @@ USER root
 
 # Install all OS dependencies for notebook server that starts but lacks all
 # features (e.g., download as all possible file formats)
-# - tini is installed as a helpful container entrypoint that reaps zombie
-#   processes and such of the actual executable we want to start, see
-#   https://github.com/krallin/tini#why-tini for details.
-# - apt-get upgrade is run to patch known vulnerabilities in apt-get packages as
-#   the ubuntu base image is rebuilt too seldom sometimes (less than once a month)
 ENV DEBIAN_FRONTEND noninteractive
 RUN apt-get update --yes && \
+    # - apt-get upgrade is run to patch known vulnerabilities in apt-get packages as
+    #   the ubuntu base image is rebuilt too seldom sometimes (less than once a month)
     apt-get upgrade --yes && \
     apt-get install --yes --no-install-recommends \
     ca-certificates \
     fonts-liberation \
     locales \
+    # - pandoc is used to convert notebooks to html files
+    #   it's not present in arm64 ubuntu image, so we install it here
     pandoc \
+    # - run-one - a wrapper script that runs no more
+    #   than one unique  instance  of  some  command with a unique set of arguments,
+    #   we use `run-one-constantly` to support `RESTARTABLE` option
     run-one \
     sudo \
+    # - tini is installed as a helpful container entrypoint that reaps zombie
+    #   processes and such of the actual executable we want to start, see
+    #   https://github.com/krallin/tini#why-tini for details.
     tini \
     wget && \
     apt-get clean && rm -rf /var/lib/apt/lists/* && \