Switch docs to MKDocs (#602)

Fixes #601. Merged in 6f87b32 from the md3 branch and did a lot of cleanup.

Changes include:

* Removed old docs build tool, templates, etc.

* Added MkDocs config file, etc.

* filename.txt => filename.md

* pythonhost.org/Markdown => Python-Markdown.github.io

* Markdown lint and other cleanup.

* Automate pages deployment in makefile with `mkdocs gh-deploy`

    Assumes a git remote is set up named "pages". Do

        git remote add pages https://github.com/Python-Markdown/Python-Markdown.github.io.git

    ... before running `make deploy` the first time.

1 files changed, 73 insertions, 0 deletions

diff --git a/docs/change_log/release-2.4.md b/docs/change_log/release-2.4.md
new file mode 100644
index 0000000..19130f1
--- /dev/null
+++ b/docs/change_log/release-2.4.md
@@ -0,0 +1,73 @@
+title:      Release Notes for v2.4
+
+Python-Markdown 2.4 Release Notes
+=================================
+
+We are pleased to release Python-Markdown 2.4 which adds one new extension
+and fixes various bugs. See the list of changes below for details.
+
+Python-Markdown supports Python versions 2.6, 2.7, 3.1, 3.2, and 3.3.
+
+Backwards-incompatible Changes
+------------------------------
+
+* The `force_linenos` configuration setting of the CodeHilite extension has been
+  marked as **Deprecated**. It had previously been marked as "Pending
+  Deprecation" in version 2.3 when a new setting `linenums` was added to replace
+  it. See documentation for the [CodeHilite Extension] for an explanation of the
+  new `linenums` setting. The new setting will honor the old `force_linenos` if
+  it is set, but `force_linenos` will raise a `DeprecationWarning` and will
+  likely be removed in a future version of Python-Markdown.
+
+[CodeHilite Extension]: ../extensions/code_hilite.md
+
+* URLs are no longer percent-encoded. This improves compatibility with the
+  original (written in Perl) Markdown implementation. Please percent-encode your
+  URLs manually when needed.
+
+What's New in Python-Markdown 2.4
+---------------------------------
+
+* Thanks to the hard work of [Dmitry Shachnev] the [Smarty Extension] has been
+  added, which implements [SmartyPants] using Python-Markdown's Extension API.
+  This offers a few benefits over a third party script. The HTML does not need
+  to be "tokenized" twice, no hacks are required to combine SmartyPants and code
+  highlighting, and we get markdown's escaping feature for free. Please try it
+  out and report bugs and/or improvements.
+
+[Dmitry Shachnev]: https://github.com/mitya57
+[Smarty Extension]: ../extensions/smarty.md
+[SmartyPants]: http://daringfireball.net/projects/smartypants/
+
+* The [Table of Contents Extension] now supports new `permalink` option for
+  creating [Sphinx]-style anchor links.
+
+[Table of Contents Extension]: ../extensions/toc.md
+[Sphinx]: http://sphinx-doc.org/
+
+* It is now possible to enable Markdown formatting inside HTML blocks by
+  appending `markdown=1` to opening tag attributes. See [Markdown Inside HTML
+  Blocks] section for details. Thanks to [ryneeverett] for implementing this
+  feature.
+
+[Markdown Inside HTML Blocks]: ../extensions/extra.md#nested-markdown-inside-html-blocks
+[ryneeverett]: https://github.com/ryneeverett
+
+* The code blocks now support emphasizing some of the code lines. To use this
+  feature, specify `hl_lines` option after language name, for example (using the
+  [Fenced Code Extension]):
+
+        ```.python hl_lines="1 3"
+        # This line will be emphasized.
+        # This one won't.
+        # This one will be also emphasized.
+        ```
+
+    Thanks to [A. Jesse Jiryu Davis] for implementing this feature.
+
+[Fenced Code Extension]: ../extensions/fenced_code_blocks.md
+[A. Jesse Jiryu Davis]: https://github.com/ajdavis
+
+* Various bug fixes have been made. See the [commit
+  log](https://github.com/Python-Markdown/markdown/commits/master) for a
+  complete history of the changes.