docs: readme correction

README.md

@@ -19,7 +19,7 @@ The fastest JSON Schema validator for Node.js and browser. Supports draft-06/07
 - support of JSON Schema draft-2019-09 features: [`unevaluatedProperties`](./json-schema.md#unevaluatedproperties) and [`unevaluatedItems`](./json-schema.md#unevaluateditems), [dynamic recursive references](./validation.md#extending-recursive-schemas) and other [additional keywords](./json-schema.md#json-schema-draft-2019-09).
 - to reduce the mistakes in JSON schemas and unexpected validation results, [strict mode](./docs/strict-mode.md) is added - it prohibits ignored or ambiguous JSON Schema elements.
 - to make code injection from untrusted schemas impossible, [code generation](./docs/codegen.md) is fully re-written to be safe and to allow code optimization (compiled schema code size is reduced by more than 10%).
-- to simplify Ajv extensions, the new keyword API that is used by all included keywords is available to user-defined keywords - it is much easier to define any keywords now, especially with subschemas.
+- to simplify Ajv extensions, the new keyword API that is used by pre-defined keywords is available to user-defined keywords - it is much easier to define any keywords now, especially with subschemas. [ajv-keywords](https://github.com/ajv-validator/ajv-keywords) package was updated to use the new API (in [v4.0.0-beta.0](https://github.com/ajv-validator/ajv-keywords/releases/tag/v4.0.0-beta.0))
 - schemas are compiled to ES6 code (ES5 code generation is also supported with an option).
 - to improve reliability and maintainability the code is migrated to TypeScript.