docs(README): Add note on JSON Schema versions for 1.8.0

Author: asyrjasalo

README.md

@@ -5,7 +5,7 @@
 [Keyword Documentation](https://asyrjasalo.github.io/RESTinstance)
 
 Updates:
-- Since 1.7.1, JSON Schema Draft 2020-12 and Draft 2019-09 are also supported
+- Since 1.8.0, JSON Schema Draft 2020-12 and Draft 2019-09 are also supported
 - Since 1.7.0, Swagger (OpenAPI 2.0) support is deprecated, and will be removed in the future
 - Since 1.7.0, OpenAPI 3.2 is supported, in addition to 3.0 and 3.1