Using Emojis in R and R Markdown

Recently I worked on some pull requests for [interactive tutorials](https://github.com/OpenIntroStat/ims-tutorials) for the OpenIntro textbook Introduction to Modern Statistics. There I came across the [package `emo`](https://github.com/hadley/emo). Its purpose is: "Easily insert emoji into R and R Markdown". This post describes some learnings on how to use this package.