Fix public beta release date at TPCiC2020 presentation

Look: https://pheix.org/tpc20cic

The slide with Looking forward! details uses slide background from Swiss Perl Workshop presentation: https://pheix.org/resources/skins/akin/img/slides/slide28.png.

On this slide Public β-release is planned on 12 Oct, 2020. Also same details in Road map at the end of SPW2019 presentation. Public β-release was released on 19.02.2021: https://pheix.org/embedded/1613295000

These slides (both SPW2019 and TPCiC) should be corrected: updated road map where Pheix public beta is Q1 2021.