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, 78 insertions, 0 deletions

diff --git a/docs/extensions/smarty.md b/docs/extensions/smarty.md
new file mode 100644
index 0000000..8c0d8cc
--- /dev/null
+++ b/docs/extensions/smarty.md
@@ -0,0 +1,78 @@
+title: SmartyPants Extension
+
+SmartyPants
+===========
+
+Summary
+-------
+
+The SmartyPants extension converts ASCII dashes, quotes and ellipses to
+their HTML entity equivalents.
+
+ASCII symbol | Replacements    | HTML Entities       | Substitution Keys
+------------ | --------------- | ------------------- | ----------------------------------------
+`'`          | ‘ ’ | `‘` `’` | `'left-single-quote'`, `'right-single-quote'`
+`"`          | “ ” | `“` `”` | `'left-double-quote'`, `'right-double-quote'`
+`<< >>`      | &laquo; &raquo; | `&laquo;` `&raquo;` | `'left-angle-quote'`, `'right-angle-quote'`
+`...`        | &hellip;        | `&hellip;`          | `'ellipsis'`
+`--`         | &ndash;         | `&ndash;`           | `'ndash'`
+`---`        | &mdash;         | `&mdash;`           | `'mdash'`
+
+Using the configuration option 'substitutions' you can overwrite the
+default substitutions. Just pass a dict mapping (a subset of) the
+keys to the substitution strings.
+
+For example, one might use the following configuration to get correct quotes for
+the German language:
+
+```python
+extension_configs = {
+    'markdown.extensions.smarty': {
+        'substitutions': {
+            'left-single-quote': '&sbquo;', # sb is not a typo!
+            'right-single-quote': '&lsquo;',
+            'left-double-quote': '&bdquo;',
+            'right-double-quote': '&ldquo;'
+        }
+    }
+}
+```
+
+!!! note
+    This extension re-implements the Python [SmartyPants]
+    library by integrating it into the markdown parser.
+    While this does not provide any additional features,
+    it does offer a few advantages. Notably, it will not
+    try to work on highlighted code blocks (using the
+    [CodeHilite] Extension) like the third party library
+    has been known to do.
+
+[SmartyPants]: http://pythonhosted.org/smartypants/
+[CodeHilite]: code_hilite.html
+
+Usage
+-----
+
+See [Extensions](index.md) for general extension usage, specify
+`markdown.extensions.smarty` as the name of the extension.
+
+See the [Library Reference](../reference.md#extensions) for information about
+configuring extensions.
+
+The following options are provided to configure the output:
+
+Option                | Default value | Description
+------                | ------------- | -----------
+`smart_dashes`        | `True`        | whether to convert dashes
+`smart_quotes`        | `True`        | whether to convert straight quotes
+`smart_angled_quotes` | `False`       | whether to convert angled quotes
+`smart_ellipses`      | `True`        | whether to convert ellipses
+`substitutions`       | `{}`          | overwrite default substitutions
+
+Further reading
+---------------
+
+SmartyPants extension is based on the original SmartyPants implementation
+by John Gruber. Please read it's [documentation][1] for details.
+
+[1]: http://daringfireball.net/projects/smartypants/