Adding initial tech presentation format

[jcarpi]

Users can use template=tech-presentation to use this new presentation template. A new \slide command can be used to create a page that looks like the title page, but has empty contents to allow users to fill in their own content.

Example Slide Usage:

\slide{My Slide Title}{
  \flushleft\textbf{\Large Some Excellent Points}
  \vspace{1em}
  \begin{itemize}
    \item My first point...
    \item A second point...
    \item And another point...
  \end{itemize}
}

Note that the end goal would be to overload \section in the tech-presentation template, but I wasn't able to make that work, so \slide was a helpful workaround in the short term.

Out of the box, the title slide looks like this...