adding reference genome on doc

app/node-app/public/pages/doc.md

@@ -16,7 +16,7 @@ http://arraymap.org/api/?db=arraymap&qcveto=1&api_out=samples&icdm_m=8,9&api_doc
 
 **Example**
 
-Query chromosome 11 at position 34439881 for the dataset 8070/3, showing a deletion: [query?chromosome=11&position=34439881&dataset=8070/3&variantClass=DEL](http://beacon-arraymap.vital-it.ch/v0.2/query?chromosome=11&position=34439881&dataset=8070/3&variantClass=DEL)
+Query chromosome 11 at position 34439881 for the dataset 8070/3, showing a deletion: [query?chromosome=11&position=34439881&reference=GRCh38&dataset=8070/3&variantClass=DEL](http://beacon-arraymap.vital-it.ch/v0.2/query?chromosome=11&position=34439881&dataset=8070/3&variantClass=DEL)
 
 
 **Outcome from the meeting with Jordi (Feb, 10, 2016):**