Fix broken link in README (#1029)

Author: danielaparker

README.md

@@ -11,7 +11,7 @@
 [![codecov.io](https://codecov.io/github/networknt/json-schema-validator/coverage.svg?branch=master)](https://codecov.io/github/networknt/json-schema-validator?branch=master)
 [![Javadocs](http://www.javadoc.io/badge/com.networknt/json-schema-validator.svg)](https://www.javadoc.io/doc/com.networknt/json-schema-validator)
 
-This is a Java implementation of the [JSON Schema Core Draft v4, v6, v7, v2019-09 and v2020-12](http://json-schema.org/latest/json-schema-core.html) specification for JSON schema validation. This implementation supports [Customizing Meta-Schemas, Vocabularies, Keywords and Formats](doc/custom-meta-schema.md).
+This is a Java implementation of the [JSON Schema Core Draft v4, v6, v7, v2019-09 and v2020-12](https://json-schema.org/specification) specification for JSON schema validation. This implementation supports [Customizing Meta-Schemas, Vocabularies, Keywords and Formats](doc/custom-meta-schema.md).
 
 In addition, [OpenAPI](doc/openapi.md) 3 request/response validation is supported with the use of the appropriate meta-schema. For users who want to collect information from a JSON node based on the schema, the [walkers](doc/walkers.md) can help. The JSON parser used is the [Jackson](https://github.com/FasterXML/jackson) parser. As it is a key component in our [light-4j](https://github.com/networknt/light-4j) microservices framework to validate request/response against OpenAPI specification for [light-rest-4j](http://www.networknt.com/style/light-rest-4j/) and RPC schema for [light-hybrid-4j](http://www.networknt.com/style/light-hybrid-4j/) at runtime, performance is the most important aspect in the design.