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, 0 insertions, 88 deletions

diff --git a/docs/extensions/footnotes.txt b/docs/extensions/footnotes.txt
deleted file mode 100644
index e9b0451..0000000
--- a/docs/extensions/footnotes.txt
+++ /dev/null
@@ -1,88 +0,0 @@
-title:      Footnotes Extension
-prev_title: Fenced Code Blocks Extension
-prev_url:   fenced_code_blocks.html
-next_title: Tables Extension
-next_url:   tables.html
-
-Footnotes
-=========
-
-Summary
--------
-
-The Footnotes extension adds syntax for defining footnotes in Markdown
-documents.
-
-This extension is included in the standard Markdown library.
-
-Syntax
-------
-
-Python-Markdown's Footnote syntax follows the generally accepted syntax of the 
-Markdown community at large and almost exactly matches [PHP Markdown Extra][]'s
-implementation of footnotes. The only differences involve a few subtleties in 
-the output.
-
-[PHP Markdown Extra]: http://michelf.com/projects/php-markdown/extra/#footnotes
-
-Example:
-
-    Footnotes[^1] have a label[^@#$%] and the footnote's content.
-
-    [^1]: This is a footnote content.
-    [^@#$%]: A footnote on the label: "@#$%".
-
-A footnote label must start with a caret `^` and may contain any inline text 
-(including spaces) between a set of square brackets `[]`. Only the first
-caret has any special meaning.
-
-A footnote content must start with the label followed by a colon and at least 
-one space. The label used to define the content must exactly match the label used
-in the body (including capitalization and white space). The content would then 
-follow the label either on the same line or on the next line. The content may 
-contain multiple lines, paragraphs, code blocks, blockquotes and most any other 
-markdown syntax. The additional lines must be indented one level (four spaces or 
-one tab). 
-
-When working with multiple blocks, it may be helpful to start the content on a 
-separate line from the label which defines the content. This way the entire block 
-is indented consistently and any errors are more easily discernible by the author.
-
-    [^1]: 
-        The first paragraph of the definition.
-
-        Paragraph two of the definition.
-
-        > A blockquote with
-        > multiple lines.
-
-            a code block
-
-        A final paragraph.
-
-
-Usage
------
-
-See [Extensions](index.html) for general extension usage, specify `markdown.extensions.footnotes`
-as the name of the extension.
-
-See the [Library Reference](../reference.html#extensions) for information about
-configuring extensions.
-
-The following options are provided to configure the output:
-
-* **`PLACE_MARKER`**:
-    A text string used to mark the position where the footnotes are rendered.
-    Defaults to `///Footnotes Go Here///`.
-
-    If the place marker text is not found in the document, the footnote
-    definitions are placed at the end of the resulting HTML document.
-
-* **`UNIQUE_IDS`**:
-    Whether to avoid collisions across multiple calls to `reset()`. Defaults to
-    `False`.
-    
-* **`BACKLINK_TEXT`**:
-    The text string that links from the footnote definition back to the position
-    in the document. Defaults to `↩`.