docs: update Simplified Chinese translation for GitHub Desktop section

[dingh5721-dotcom]

The Simplified Chinese README (translations/README.zh-CN.md) is missing the "Using GitHub Desktop" section that was added to the English README.
I plan to add this section and fix typos to keep the translation up-to-date.

[KOMMINITHIN]

Hi, I would like to work on this issue!

[KOMMINITHIN]

I have submitted a pull request for this issue here: #119434

[satyammishra8-1]

hi i would like to contribute to this issue.

[MilyaTatarka]

Готов помочь с решением этой задачи.

[YadhuKiran]

hii i woudld like to work on this issue

[cdev-x]

Hi! I'd like to work on this issue if it's still available.

[AkashGowdaNC]

Hi! I'd like to help update this translation. Could you please assign this issue to me?