.github/FUNDING.yml: Remove LiberaPay; add Bitcoin address

* .github/FUNDING.yml: Remove LiberaPay for now.  Add my Bitcoin address.

.github/FUNDING.yml

@@ -6,7 +6,8 @@ open_collective: # Replace with a single Open Collective username
 ko_fi: # Replace with a single Ko-fi username
 tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
 community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
-liberapay: avp
+liberapay: # avp
 issuehunt: # Replace with a single IssueHunt username
 otechie: # Replace with a single Otechie username
-custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']
+# Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']
+custom: ['https://www.blockchain.com/explorer/addresses/btc/bc1qp7vwxnp4z05fgedfsrqeqvt89fjwnnghng0vp5']