Added new file shortcode and added better checks in figure and img shortcodes.

README.md

@@ -455,7 +455,7 @@ Possible parameters are:
 * caption (only figure)
 * class
 * height
-* link (only figure)
+* link
 * size (only works if image is inside /assets dir)
 * src
 * title (only figure)
@@ -469,6 +469,17 @@ Only "src" is none optional but you really should set "alt" as well.
 * If only width or only height is set the other value will be proportionally calculated.
 
 
+### File
+
+Creates a link to a file in static or in assets directory.
+
+Possible parameters are:
+
+* class
+* name
+* src
+
+
 ### Search
 
 Creates a search page for the site, [see more above](#search).