Correct region names

[Kemi-Elizabeth]

Where on docs.platform.sh should be changed?

All region names are wrong so they need to be corrected.

For example: ch-1.upsun.com should be ch-1.platform.sh as there is no difference between psh and Upsun here.

What exactly should be updated?

https://docs.upsun.com/development/regions.html

Additional context

No response