Add a `http_proxy` setting

[TENX-S]

Check for existing issues

• [X] Completed

Describe the feature

FYI, programmers in China face restrictions from the Great Firewall(GFW) and require a VPN service to access the internet freely. When I launch Zed, it automatically downloads the LSP server, which is blocked by the GFW and fails to complete. Therefore, I need to set the http_proxy env variable in a terminal session and open Zed using the CLI.

It would be very helpful if there were settings related to http_proxy. Take VS Code as an example:

If applicable, add mockups / screenshots to help present your vision of the feature

No response