add support for custom fields

src/components/presentational/Card/CustomField.js

@@ -0,0 +1,14 @@
+import React from 'react'
+import marked from 'marked'
+
+const CardCustomField = ({ field, value }) => (
+  <div className='card-cell'>
+    <p>
+      <i className='material-icons left'>{field.icon}</i>
+      <b>{field.title ? `${field.title}: ` : '- '}</b>
+      {field.kind === 'text' ? value : marked(`[${value}](${field.value})`)}
+    </p>
+  </div>
+)
+
+export default CardCustomField