Update Merril Edge fido2 support (2factorauth#8472)

Co-authored-by: Viraaj Navalekar <viraajn@outlook.com>

Author: viraajn

entries/m/merrilledge.com.json

@@ -7,9 +7,10 @@
     ],
     "url": "https://www.merrilledge.com/",
     "tfa": [
-      "sms"
+      "sms",
+      "u2f"
     ],
-    "documentation": "https://github.com/2factorauth/twofactorauth/issues/2275",
+    "documentation": "https://www.ml.com/privacy-and-security-center/usb-security-key.html",
     "categories": [
       "investing"
     ],