Fix syntax errors in vignettes: remove spaces in code block delimiters (#1218)

Author: VincentGuyader

vignettes/a-getting-started.Rmd

@@ -26,7 +26,7 @@ knitr::opts_chunk$set(
 ## Installing {golem}
 
 You can install the stable version of `{golem}` from CRAN:
-``` {r}
+```{r}
 install.packages("golem")
 ```
 
@@ -205,4 +205,3 @@ rstudioapi::navigateToFile("dev/02_dev.R")
 ```{r, eval = TRUE, include = FALSE}
 try(fs::dir_delete(x), silent = TRUE)
 ```
-

vignettes/g-contribute.Rmd

@@ -44,23 +44,23 @@ Golem package follows the `grkstyle` style guide. Please make sure to follow the
 
 If your are using RStudio, you can set the `grkstyle` style guide as the default style guide for the package by running the following code:
 
-``` {r eval=FALSE}
+```{r eval=FALSE}
 options(
   styler.addins_style_transformer = "grkstyle::grk_style_transformer()"
 )
 ```
 
 If your are using VSCode, you can set the `grkstyle` style guide as the default style guide for the package by running the following code:
 
-``` {r eval=FALSE}
+```{r eval=FALSE}
 options(languageserver.formatting_style = function(options) {
   grkstyle::grk_style_transformer()
 })
 ```
 
 It's also possible to style one file at a time by running the following code:
 
-``` {r eval=FALSE}
+```{r eval=FALSE}
 grkstyle::grk_style_file("README.Rmd")
 ```