Gollum is a simple wiki system built on top of Git. A Gollum Wiki is
simply a git repository of a specific nature:

    - A Gollum repository's contents are human-editable. Pages are
      unique text files which may be organized into directories any
      way you choose, as long as they have a recognized file
      extension. Other content can also be included, for example
      images, PDFs and headers/footers.
    - Gollum pages:
        - May be written in a variety of markup languages.
        - Can be edited with your favourite system editor or IDE or
          with the built-in web interface.
        - Can be displayed in all versions, and can easily be rolled
          back.
    - Gollum supports advanced functionality like UML diagrams,
      macros, metadata, and more.
