docs(hedgedoc): Add matrix link to helm chart

charts/hedgedoc/Chart.yaml

@@ -6,6 +6,8 @@ description: |
   (Be aware: This is currently a PoC and not necessarily fit for all use-cases. It is mainly built for use with external PostgresQL databases.)
 annotations:
   artifacthub.io/links: |
+    - name: matrix
+      url: https://chat.hedgedoc.org/
     - name: documentation
       url: https://docs.hedgedoc.org/
 home: https://hedgedoc.org