There are many different ways to make R presentations and one of them is Slidify.
R presentations are presentations coded as Rmarkdown and then translated to HTML using the R programming language framework.
Slidify uses whisker to render the final html by passing the parsed data to the layout file. Whisker is a Mustache implementation in R confirming to the Mustache specification. Mustache is a logicless templating language, meaning that no programming source code can be used in your templates.
There are tons of tutorials on slidify. In my case, I focused on the installation process as well as providing information and examples that helps reduce common mistakes that are made during your initial learning. As best example to learn I have written a Slidify tutorial that you can download and modify.