Add Swahili (Kiswahili) Translation for GitHub Desktop Tutorial

[SRupia]

Hi maintainers! 👋

I would like to contribute a Swahili (Kiswahili) translation for the GitHub Desktop tutorial. Swahili is widely spoken in East Africa, including Tanzania, Kenya, Uganda, and Rwanda, and a translation would help many new users understand and use GitHub more easily.

I am happy to submit a complete translation as a pull request once the contribution guidelines are confirmed.

Thank you for considering this!

[Katherinyame]

Hi, I'm a student conrtibutor and I'd like to work on this issues. Please let me know if its available. Thank you