README points to outdated 1.0.x documentation

[linghengqian]

• README points to outdated 1.0.x documentation. See https://github.com/spring-projects/spring-security-kerberos/blob/v2.1.0/README.adoc#documentation .

Be sure to read the http://docs.spring.io/spring-security-kerberos/docs/1.0.x/reference/htmlsingle/ . Extensive JavaDoc for the Spring Security Kerberos code is also available in the http://docs.spring.io/spring-security-kerberos/docs/1.0.x/api/ .

• But according to https://spring.io/projects/spring-security-kerberos , Spring Security Kerberos 2.1.0 has been released.

[rwinch]

Thank you for the report @linghengqian Would you be interested in submitting a pull request?

[linghengqian]

Thank you for the report @linghengqian Would you be interested in submitting a pull request?

• I have opened #262 .