docs: link to $data reference proposal, closes #51

README.md

@@ -328,7 +328,7 @@ __Please note__:
 
 ## $data reference
 
-With `$data` option you can use values from the validated data as the values for the schema keywords. See [proposal](https://github.com/json-schema/json-schema/wiki/$data-(v5-proposal)) for more information about how it works.
+With `$data` option you can use values from the validated data as the values for the schema keywords. See [proposal](https://github.com/json-schema-org/json-schema-spec/issues/51) for more information about how it works.
 
 `$data` reference is supported in the keywords: const, enum, format, maximum/minimum, exclusiveMaximum / exclusiveMinimum, maxLength / minLength, maxItems / minItems, maxProperties / minProperties, formatMaximum / formatMinimum, formatExclusiveMaximum / formatExclusiveMinimum, multipleOf, pattern, required, uniqueItems.