Use https scheme in examples

[php-coder]

Inspired by https://spring.io/blog/2019/06/10/announcing-nohttp I'd like to use HTTPS instead of HTTP for Thymeleaf URLs.

I see that documentation have examples with http:

xmlns:th="http://www.thymeleaf.org"

Here is the question: can I simply replace http by https in the xmlns? And if yes, should we update documentation to use https URLs in examples?