add: MaxiPool

see also mempool#66

Author: 0xB10C

pools/maxipool.json

@@ -0,0 +1,11 @@
+{
+  "id": 150,
+  "name": "MaxiPool",
+  "addresses": [
+    "36r3YqAXWpyqNcczjCBdHrYZ3m8X56WDzx"
+  ],
+  "tags": [
+    "/MaxiPool/"
+  ],
+  "link": "https://maxipool.org/"
+}