Minor vignette edit

Author: alandipert

vignettes/intro_htmlwidgets.Rmd

@@ -241,7 +241,7 @@ This should open up the `sparklines()` widget in your browser. If it does, congr
 
 ### Shiny integration
 
-The scaffolding template already provides the glue you need to get your **reactR** widget to render in **shiny**. The two relevant functions are `renderSparklines()` and `sparklinesOutput()`. You shouldn't need to modify these functions -- they should work out of the box. You will, however, want to modify the example **shiny** app in the `app.R` file: 
+The scaffolding template already provides the glue you need to get your **reactR** widget to render in **shiny**. The two relevant functions are `renderSparklines()` and `sparklinesOutput()`. You shouldn't need to modify these functions — they should work out of the box. You will, however, want to modify the example **shiny** app in the `app.R` file:
 
 ```{r}
 library(shiny)