Use SimpleFigure in Texinfo writer.

Author: argent0

src/Text/Pandoc/Writers/Texinfo.hs

@@ -123,8 +123,7 @@ blockToTexinfo (Plain lst) =
   inlineListToTexinfo lst
 
 -- title beginning with fig: indicates that the image is a figure
-blockToTexinfo (Para [Image attr txt (src,tgt)])
-  | Just tit <- T.stripPrefix "fig:" tgt = do
+blockToTexinfo (SimpleFigure attr txt (src, tit)) = do
       capt <- if null txt
               then return empty
               else (\c -> text "@caption" <> braces c) `fmap`