Since slim/slim-skeleton is mentioned in the main page (https://www.slimframework.com/) I assume this an official way to go with Slim framework. There are several strange things in slim/slim-skeleton, but one bothers me a lot.
<Files .htaccess>
order allow,deny
deny from all
</Files>
in both .htaccess files. This is Apache 2.2 syntax and now it is deprecated. So why is it there? As far as I know slim/slim-skeleton is not that old and abandoned…
I know that example in Slim documentation is correct. The question was more about relationships between Slim and slim-skeleton. I assume both are created by the same people.
The core maintainers are the same, but the contributors are different for each project. Thus, the code samples and documentation may not be perfectly synchronized.
I think your initial question about the deprecated syntax would be a good one for the slim-skeleton issues.