Clarify supported Linux versions

[domdfcoding]

Describe the bug

There is a conflict between the README and the downloads page as to the supported Linux versions.
The README lists in particular Ubuntu 20.04LTS and Fedora 33 as minimum versions, but the downloads page wants the newer Ubuntu 22.04 and Fedora 37. I've tested with Ubuntu 20.04 and the .deb will install and the app launch.

Add logs

N/A

Steps to reproduce

1. Visit https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher?tab=readme-ov-file#supported-operating-systems
2. Visit https://heroicgameslauncher.com/downloads
3. See that the supported Linux versions are stricter on the downloads page.

Expected behavior

The minimum supported Linux version is consistent to avoid confusion.

Screenshots

No response

Heroic Version

Latest Stable

System Information

• OS [e. g. "Ubuntu"]: Ubuntu 20.04

Additional information

No response