remove run examples as their not needed

- try fixing issues with code chunks in posterdown_betterland and betterport

- including them seems to generate layout errors.
diff --git a/DESCRIPTION b/DESCRIPTION
index 3f554ef..b6a0cbf 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -16,7 +16,7 @@
       person(given = "Luke",
              family = "Johnston",
              role = "ctb"))
-Description: Use rmarkdown and pagedown to generate
+Description: Use 'rmarkdown' and 'pagedown' to generate
     HTML and PDF conference posters.
 License: MIT + file LICENSE
 URL: https://github.com/brentthorne/posterdown