add merchant hodlmonkey

_data/merchants.yml

@@ -231,6 +231,8 @@
       url: https://www.hammockuniverseusa.com/
     - name: Handcrafted goods
       url: https://mychain.store/
+    - name: Hodlmonkey - Crypto T-Shirts
+      url: https://hodlmonkey.com/
     - name: InvestmentArt
       url: http://investmentart.org/
     - name: Mushroom cultures, mushroom growing supplies, seeds