Incorrect Spring Authorization Server Reference hyperlink on README.adoc

[OSKUDA]

Describe the bug
The hyperlink for the 'Spring Authorization Server Reference' on README.adoc is incorrect and points to an non existing resource. Currently redirects the user to 'https://docs.spring.io/spring-authorization-server/docs/current/reference/html/' instead of 'https://docs.spring.io/spring-authorization-server/reference/'

To Reproduce
Click on the 'Spring Authorization Server Reference' link on README.adoc
HTTP 404 is returned 'Oops! The page can’t be found.'

Expected behavior
Should redirect the user to current version of 'Spring Authorization Server Reference' website i.e. 'https://docs.spring.io/spring-authorization-server/reference/'