fix typo

Author: maurolepore

vignettes/allcontributors.Rmd

@@ -315,7 +315,7 @@ lines of text.
 
 The shortest possible way of acknowledging your contributors would be like this:
 ```{r short, eval = FALSE}
-add_contributors (num_sectons = 1, format = "text")
+add_contributors (num_sections = 1, format = "text")
 ```
 which would in this case convert the above into the single list of,