Added section on why the json structure is how it is (#14)

* Added section on why the json structure is how it is

This talks about caching and combining data, there is no code in this section.

* Added section on caching.

This also includes a diagram written using ditaa, so the Emacs config adds
support for ditaa and the Docker image now installs ditaa so the ASCII art can
be rendered into something prettier

Author: arbor-acaird

render/Dockerfile

@@ -6,6 +6,9 @@ RUN apt-get install -y texlive
 RUN apt-get install -y texlive-pictures
 RUN apt-get install -y texlive-latex-extra
 RUN apt-get install -y python-pygments
+RUN apt-get install -y ditaa
+RUN mkdir -p /usr/share/emacs/25.2/lisp/contrib/scripts/
+RUN /bin/ln -s /usr/share/ditaa/ditaa.jar /usr/share/emacs/25.2/lisp/contrib/scripts/
 COPY export.el /
 COPY render.sh /
 ENTRYPOINT ["/bin/bash", "render.sh"]

render/export.el

@@ -27,4 +27,9 @@
                                  ("breakafter" "+")
                                  ))
 
+(setq org-confirm-babel-evaluate 'nil)
+(org-babel-do-load-languages
+      'org-babel-load-languages
+      '((ditaa .t)
+       ))
 (setq org-export-with-smart-quotes t)