Update implementations.json to include waraft

Author: cowang4

implementations.json

@@ -2822,5 +2822,23 @@
             "logCompaction": true,
             "persistence": true
         }
+    },
+    {
+        "repoURL": "https://github.com/WhatsApp/waraft",
+        "name": "waraft",
+        "authors": [
+            {
+                "name": "WhatsApp",
+                "github": "whatsapp"
+            }
+        ],
+        "language": "Erlang",
+        "license": "Apache-2.0",
+        "features": {
+            "basic": true,
+            "membershipChanges": true,
+            "logCompaction": true,
+            "persistence": true
+        }
     }
 ]