Background Image Support

[ming900518]

Problem

In VSCode and IntelliJ, there's an option or extension to set a background image, which is missing in Zed.

Solution Proposal

I forked this project and added an option called background.image_file to the experimental.theme_overrides setting.

Repo: https://github.com/ming900518/zed/tree/background-image

{
  "experimental.theme_overrides": {
    "background.image_file": "*FILE PATH*",
  }
}

With this option set, Zed will read the image file specified and render it behind the UI elements, users can combine this new option with other background color options to create beautiful blending.

I would like to see this feature officially supported by Zed, so I looked up the CONTRIBUTING.md and opened this discussion to propose adding this feature.

I'm not quite sure if I should open the pull request directly or wait for the Zed team to respond with this proposal. If Zed team is interested and the pull request is preferred or required for proposing changes. Please let me know.