DonĀ“t set default img width in css to make it overridable

by fig.width

Change-Id: Ib57f1412f7b3191805e4de00ae8b5b17ba4ffec4
diff --git a/inst/rmarkdown/templates/posterdown_ids/resources/template.html b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
index d16973d..aa73b31 100644
--- a/inst/rmarkdown/templates/posterdown_ids/resources/template.html
+++ b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
@@ -273,10 +273,6 @@
 margin-block-end: 0.25em;
 }
 
-.poster_body img {
-  width: 100%;
-}
-
 .footnotes {
   font-family: Fira Sans Condensed;
 }