posterdown_memoir phased to posterdown_pdf

Fully-ish customised sizing of the poster and colours :partly_sunny:
diff --git a/man/posterdown_memoir.Rd b/man/posterdown_pdf.Rd
similarity index 79%
rename from man/posterdown_memoir.Rd
rename to man/posterdown_pdf.Rd
index f903bca..add1004 100644
--- a/man/posterdown_memoir.Rd
+++ b/man/posterdown_pdf.Rd
@@ -1,10 +1,10 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/posterdown_memoir.R
-\name{posterdown_memoir}
-\alias{posterdown_memoir}
+% Please edit documentation in R/posterdown_pdf.R
+\name{posterdown_pdf}
+\alias{posterdown_pdf}
 \title{Posterdown PDF format (using 'memoir' document class)}
 \usage{
-posterdown_memoir(..., keep_tex = TRUE)
+posterdown_pdf(..., keep_tex = TRUE)
 }
 \arguments{
 \item{...}{Additional arguments to \code{rmarkdown::pdf_document}}