Add Plex Chinese TC to [What’s new]

[mjabbink]

When IBM Plex Chinese TC is released on GitHub, please plan to have this go up soon after for communication purposes.

Image reference

copy After more than two years of design and development, IBM Plex Chinese TC (Traditional) is now available. This will soon be followed by a Plex Chinese SC (Simplified) version, making Plex Chinese a valuable landmark for our users. Plex is open source and free to use. Additionally, Plex is available in Arabic, Cyrillic, Devanagari, Greek, Hebrew, Japanese, Korean, and Thai. You can find more information about the Plex typeface family in the IBM Design Language site and download IBM Plex Sans TC from GitHub.