Decrease default titlebox_height to 7.5%

Change-Id: Icbdbdfa4ef7ba7db8b24e641eb5891651fdf0634
diff --git a/inst/rmarkdown/templates/posterdown_ids/resources/template.html b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
index 9e01167..6732db0 100644
--- a/inst/rmarkdown/templates/posterdown_ids/resources/template.html
+++ b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
@@ -68,7 +68,7 @@
 }
 .title_container {
 width: $if(titlebox_borderwidth)$calc(100% - $titlebox_borderwidth$ - $titlebox_borderwidth$)$else$100%$endif$;
-height: $if(titlebox_borderwidth)$calc($if(titlebox_height)$$titlebox_height$$else$10%$endif$ - $titlebox_borderwidth$ - $titlebox_borderwidth$)$else$$if(titlebox_height)$$titlebox_height$$else$10%$endif$$endif$;
+height: $if(titlebox_borderwidth)$calc($if(titlebox_height)$$titlebox_height$$else$7.5%$endif$ - $titlebox_borderwidth$ - $titlebox_borderwidth$)$else$$if(titlebox_height)$$titlebox_height$$else$7.5%$endif$$endif$;
 overflow: hidden;
 border: $if(titlebox_borderwidth)$$titlebox_borderwidth$$else$0$endif$ solid $if(titlebox_bordercol)$$titlebox_bordercol$$else$$if(primary_colour)$$primary_colour$$else$#f18700$endif$
 $endif$;