Added a default syntax-highlighting style to Markdown highlighter.

There was previously no default style defined, so if for whatever
reason, one was not supplied, the code could throw an error. The
default has been set to text.

Signed-off-by: Byron Sanchez <bfs5030@gmail.com>
Added first version of table-header formatter code to markdownifier.

In order to implement responsive tables, table headers and table
columns need to have a matching axis attribute. This code scans
a rendered html file (the markdownifier output) and scans for any
tables that contain headers. The header values are then copied and
stored in the axis attributes for the corresponding header and column
values.

The axis attribute is later used to implement a responsive version of
tables where the header information is always next to the column values.
In other words, in small screens the table becomes a list.

Signed-off-by: Byron Sanchez <bfs5030@gmail.com>
Styled the responsive tables.

Added the necessary CSS styles and media queries so that responsive
tables work properly.

Signed-off-by: Byron Sanchez <bfs5030@gmail.com>
Updated footer copyright notice.

Signed-off-by: Byron Sanchez <bfs5030@gmail.com>