Add posterdown_betterland

better poster design for posterdown users.
diff --git a/R/posterdown_html.R b/R/posterdown_html.R
index 4ed2b10..477c95d 100644
--- a/R/posterdown_html.R
+++ b/R/posterdown_html.R
@@ -1,5 +1,4 @@
 #' Posterdown HTML format (using bookdown::html_document2)
-#'
 #' @inheritParams pagedown::poster_relaxed
 #' @param ... Additional arguments to \code{rmarkdown::html_document}
 #'
@@ -18,3 +17,12 @@
 	css = NULL) {
 	pagedown::poster_relaxed(..., css = css, template = template)
 }
+#' @description The output format \code{poster_betterland()} mimics the style of the
+#' \dQuote{BetterPoster} movement from twitter.
+#' @rdname posterdown_html
+#' @export
+posterdown_betterland <- function(...,
+                            template = find_resource("posterdown_betterland", "template.html"),
+                            css = NULL) {
+  pagedown::poster_relaxed(..., css = css, template = template)
+}