Added form hint about markdown for the project description

app/assets/stylesheets/common.scss

@@ -921,3 +921,8 @@ p.time {
   -moz-box-shadow: 0 1px 2px rgba(0,0,0,.1);
   box-shadow: 0 1px 2px rgba(0,0,0,.1);
 }
+
+.hint {
+  font-style: italic;
+  color: #999;
+}

app/views/projects/_form.html.haml

@@ -48,7 +48,9 @@
     
   .clearfix
     = f.label :description
-    .input= f.text_area :description, :placeholder => "project description", :class => "xlarge", :rows => 4
+    .input
+      = f.text_area :description, :placeholder => "project description", :class => "xlarge", :rows => 4
+      %p.hint Markdown is enabled.
   %br