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, 58 insertions, 0 deletions

diff --git a/docs/extensions/tables.md b/docs/extensions/tables.md
new file mode 100644
index 0000000..2bea470
--- /dev/null
+++ b/docs/extensions/tables.md
@@ -0,0 +1,58 @@
+title: Tables Extension
+
+Tables
+======
+
+Summary
+-------
+
+The Tables extension adds the ability to create tables in Markdown documents.
+
+This extension is included in the standard Markdown library.
+
+Syntax
+------
+
+Tables are defined using the syntax established in [PHP Markdown Extra][php].
+
+[php]: http://www.michelf.com/projects/php-markdown/extra/#table
+
+Thus, the following text (taken from the above referenced PHP documentation):
+
+```md
+First Header  | Second Header
+------------- | -------------
+Content Cell  | Content Cell
+Content Cell  | Content Cell
+```
+
+will be rendered as:
+
+```html
+<table>
+  <thead>
+    <tr>
+      <th>First Header</th>
+      <th>Second Header</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>Content Cell</td>
+      <td>Content Cell</td>
+    </tr>
+    <tr>
+      <td>Content Cell</td>
+      <td>Content Cell</td>
+    </tr>
+  </tbody>
+</table>
+```
+
+Usage
+-----
+
+See [Extensions](index.md) for general extension usage, specify
+`markdown.extensions.tables` as the name of the extension.
+
+This extension does not accept any special configuration options.