typo: profivs -> profvis (#640)

scaling-performance.Rmd

@@ -215,7 +215,7 @@ I'll start by introducing the flame graph, the visualisation used for profiling,
 Across programming languages, the most common tool used to visualise profiling data is the **flame graph**.
 To help you understand it, I'm going to start by revisiting the basics of code execution, then build up progressively to the final visualisation.
 
-To make the process concrete, we'll work with following code where I use `profivs::pause()` (more on that shortly) to indicate work being done:
+To make the process concrete, we'll work with following code where I use `profvis::pause()` (more on that shortly) to indicate work being done:
 
 ```{r}
 library(profvis)