fix data representation on blog posts

The date of news and use cases (or, in the future, blog posts) is ugly / wrong due to the abbreviated month. It 1) lacks a space after the point and 2) doesn't handle short months that aren't truncated correctly. Also, there shouldn't be a fullstop after the "day number" when using the month as word:

1. Thu, 16.Jun.2022
2. Fri, 20.May.2022

I propose Thu, 16 Jun. 2022; 20 May 2022 (please mind, 14 Sept. 2022!) or, probably simpler, just 16.06.2022 etc.