Update RMarkdown file

Include

    source: Rmd

in the YAML header.

Author: rgaiacs

_episodes/06-rmarkdown-example.md

@@ -1,4 +1,5 @@
 ---
+source: Rmd
 title: "Using RMarkdown"
 teaching: 10
 exercises: 2
@@ -77,8 +78,7 @@ ggplot(diamonds, aes(x = carat,  y = price, color = cut)) +
 ~~~
 {: .r}
 
-<img src="../fig/rmd-plot-example-1.png" title="plot of chunk plot-example"
-     alt="plot of chunk plot-example" style="display: block; margin: auto;" />
+<img src="../fig/rmd-plot-example-1.png" title="plot of chunk plot-example" alt="plot of chunk plot-example" style="display: block; margin: auto;" />
 
 For the challenges and their solutions, you need to pay attention to where the
 `>` go and where to leave blank lines. You can include code chunks in both the

_episodes_rmd/06-rmarkdown-example.Rmd

@@ -1,4 +1,5 @@
 ---
+source: Rmd
 title: "Using RMarkdown"
 teaching: 10
 exercises: 2