Add my example to the moderncv usage

Here is a list of what I modified:
+ Use the today command to show the date when I last modified this document.
+ Put the dates on the right hand side, instead of at the beginning of each row.
+ Add a contents section. This is recommended for a document with more than 10 pages.
+ Add the page number at the bottom right of each page.
+ Utilize the input command to add a section directly from another .tex file. When each section is long, this keeps the master document short and easy to maintain.

input-presentations-yyyy-mm-dd.tex

@@ -0,0 +1,5 @@
+\section{Presentations}
+
+\cvitem{$\bullet$}{\textbf{Presentation Title:} Description here. Is it a poster, contributed talk, or an invited talk? Conference ZZZ, January 2018.}
+
+\cvitem{$\bullet$}{\textbf{Undergraduate Presentation:} Description here. What is this presentation about? University of Somewhere, April 2016.}