Update to v0.1.2 with HTML support

moved posterdown_pdf to posterdown_latex, added posterdown_html, added to ReadME, added ciation file. added @shedimus  as contributor in Description file.
diff --git a/man/posterdown_pdf.Rd b/man/posterdown_latex.Rd
similarity index 61%
rename from man/posterdown_pdf.Rd
rename to man/posterdown_latex.Rd
index a0e5906..2cf4ce7 100644
--- a/man/posterdown_pdf.Rd
+++ b/man/posterdown_latex.Rd
@@ -1,9 +1,12 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/posterdown_pdf.R
-\name{posterdown_pdf}
+% Please edit documentation in R/posterdown_latex.R
+\name{posterdown_latex}
+\alias{posterdown_latex}
 \alias{posterdown_pdf}
-\title{Posterdown PDF format (using Memoir LaTeX document class)}
+\title{Posterdown LaTeX format (using Memoir LaTeX document class)}
 \usage{
+posterdown_latex(..., keep_tex = TRUE)
+
 posterdown_pdf(..., keep_tex = TRUE)
 }
 \arguments{
@@ -16,7 +19,8 @@
   \code{\link[rmarkdown:render]{render}}
 }
 \description{
-Posterdown PDF format (using Memoir LaTeX document class)
+Legacy function for the OG's of posterdown.
+This will remain untouched from here on out (Feb 6 2019).
 }
 \examples{