Avoid page break in source code

Change-Id: Idf2fc6061b322f89311b72976c2e1ddc6b34c240
diff --git a/inst/rmarkdown/templates/posterdown_ids/resources/template.html b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
index 22ae0ed..4b779ac 100644
--- a/inst/rmarkdown/templates/posterdown_ids/resources/template.html
+++ b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
@@ -315,7 +315,7 @@
   page-break-after: avoid;
 }
 
-table, figure {
+table, figure, .sourceCode {
   page-break-inside: avoid;
 }