This repository is *not* open source.  In the past I
just did not put a license file here and that would
have been sufficient to get the meaning across but
apparently some people have a different understanding
of how licensing works.

Notice that the website says that content is licensed
under the Creative Commons attribution-noncommercial-
sharealike License.  This does not apply for the
repository however and only applies to the text on the
website that is generated from the source files in this
repository.

FAQ part:

Why is it on github then?
  So that people can see how rstblog is being used, for
  learning purposes, because you can use the git history
  to track changes being made, so that you can help me
  fix typos by sending pull requests etc.

Why is only the text on the website creative commons
licensed and not the source files?
  Because it expresses the intent I have for it.  You are
  allowed to republish the content under the terms of the
  license.

How can you do pull requests if the sources are not
open source?
  Because I am the copyright holder and from a legal point
  of view I grant you the right to correct a mistake in my
  work which then becomes part of the result.  Furthermore
  I only accept pull requests for minor modifications that
  for which you cannot claim copyright anyways which makes
  it possible for me to accept your changes without you
  having to surrender your rights.

Aren't you taking this too far?
  What protects open source developers is copyright and
  licenses.  When it comes to licenses I take this very
  serious indeed.  Independent of me taking this stuff
  very serious it does however not mean that I will
  become an asshole when it comes to enforcing this.  I
  will send you an unhappy mail or complain about this
  through twitter or somehow else but I am a person of
  reason.  If you think you want some part of the website
  licensed for your personal use there are ways to do
  that if you are nice.

TL;DR: NOT OPEN SOURCE