Correctly render title page

[jeremy-audet]

The value attached to pandoc's --metadata is escaped. Consequently, setting a value through the command line, like this:

-M title="\Huge{\textbf{${TITLE}}}"

…results in that literal text displaying in the document. A solution is to use a flag which doesn't escape its value.

Fix: #152

[jeremy-audet]

I barely know anything about latex or pandoc, so if this is a terrible PR, just shoot it down. No offense will be taken. I just trawled through the pandoc manual a bit to come up with this solution.