Add some FOSS content

[IronSim]

Thank you very much for this awesome list.

i found 3 more useful FOSS software which i think, might fit well to be added here. I tried to contribute, but i'm very new. So i try it this way (sorry if this is wrong)

Authenticators

Aegis -

Image editors

Darktable

VPN

Wireguard

[geraldohomero]

Added here

Commit

[geraldohomero]

If you want to contribute, please you can read https://github.com/geraldohomero/best-foss-alternatives/blob/main/CONTRIBUTING.md

Or you can just add a new issue with your request