posterdown_memoir phased to posterdown_pdf

Fully-ish customised sizing of the poster and colours :partly_sunny:
diff --git a/.Rproj.user/441ADA46/sources/prop/6CC86257 b/.Rproj.user/441ADA46/sources/prop/6CC86257
new file mode 100644
index 0000000..7a73a41
--- /dev/null
+++ b/.Rproj.user/441ADA46/sources/prop/6CC86257
@@ -0,0 +1,2 @@
+{
+}
\ No newline at end of file