Provide straightforward example for JWKS

[poovamraj]

Changes

README has an example with an "imaginary" class. This is causing confusion with library users. Hence we are providing a straightforward example with our jwks-rsa-java library

References

https://github.com/auth0/java-jwt/issues/599 https://github.com/auth0/java-jwt/issues/285

Testing

• [ ] This change adds test coverage
• [x] This change has been tested on the latest version of Java or why not

Checklist

• [x] I have read the Auth0 general contribution guidelines
• [x] I have read the Auth0 Code of Conduct
• [x] All existing and new tests complete without errors