add posterdown_betterport

portrait template for better poster design has been added

- support for longer author list if needed, can specify various authors to be highlited in the begining of the list.

- better responsiveness to spacing when changinf poster size

-  may need to go back and ensure YAML options amon all templates are more standardized.
diff --git a/R/posterdown_html.R b/R/posterdown_html.R
index 477c95d..f4395ae 100644
--- a/R/posterdown_html.R
+++ b/R/posterdown_html.R
@@ -26,3 +26,12 @@
                             css = NULL) {
   pagedown::poster_relaxed(..., css = css, template = template)
 }
+#' @description The output format \code{poster_betterport()} mimics the style of the
+#' \dQuote{BetterPoster} movement from twitter.
+#' @rdname posterdown_html
+#' @export
+posterdown_betterport <- function(...,
+                                  template = find_resource("posterdown_betterport", "template.html"),
+                                  css = NULL) {
+  pagedown::poster_relaxed(..., css = css, template = template)
+}