Support attachements in metadata fields (fixes #77)

Change-Id: Ia5be6ec851ef318d89b115ac814663dc32da3484
diff --git a/dev/demo/matchdemo.js b/dev/demo/matchdemo.js
index f7fd779..4264783 100644
--- a/dev/demo/matchdemo.js
+++ b/dev/demo/matchdemo.js
@@ -593,6 +593,12 @@
         },
         {
           "@type":"koral:field",
+          "key":"link",
+          "type":"type:attachement",
+          "value":"data:application/x.korap-link;title=Wikipedia,https://de.wikipedia.org/wiki/Beispiel"
+        },
+        {
+          "@type":"koral:field",
           "key":"docTitle",
           "type":"type:text",
           "value":"Wikipedia, Artikel mit Anfangszahl 2, Teil 64"