Update interfaces.md - Changed one of the examples to be self consist…

…ent. It was contradicting itself. (#3384)

* Update interfaces.md

Edited the Interface documentation so the interface fields are correct.

* Update docs/types/interfaces.md

Co-authored-by: Patrick Arminio <patrick.arminio@gmail.com>

---------

Co-authored-by: Patrick Arminio <patrick.arminio@gmail.com>

docs/types/interfaces.md

@@ -146,7 +146,7 @@ class FieldError(Error):
 class PasswordTooShort(FieldError):
     message: str
     field: str
-    fix: str
+    min_length: int
 ---
 interface Error {
   message: String!