allow to custom style img

Author: auloin

layouts/shortcodes/img.html

@@ -6,4 +6,4 @@
   {{- end -}}
 {{- end -}}
 
-<img src="{{ $src }}" alt="{{ .Get "alt" }}" class="{{ .Get "class" }}" />
+<img src="{{ $src }}" alt="{{ .Get "alt" }}" style="{{ .Get "style" }}" class="{{ .Get "class" }}" />