add thekavasociety to merchants list

_data/merchants.yml

@@ -265,6 +265,8 @@
       url: https://synntechgaming.com
     - name: Stamp Monero
       url: https://stampmonero.com/
+    - name: The Kava Society - Kava tea
+      url: https://kavasociety.nz/
     - name: Xusah Boutique
       url: https://xusah.boutique/
     - name: Judit Mátyus - Jewelry