You can specify extensions you'd like people to install (or at least recommend them) when they open your project with VSCode through a .vscode/extensions.json file that looks like this, for example

{
  "recommendations": ["Vue.volar", "lokalise.i18n-ally"]
}

You can learn more about it in their documentation, https://code.visualstudio.com/docs/configure/extensions/extension-marketplace#_workspace-recommended-extensions.

It would be great if Zed had a similar feature so people using Zed on my projects would know what extensions to install to have a proper developer experience.

As a workaround we can mention them in the README, for example, but less people will tend to look at it. Workspace recommendations shows a whole section about it in extensions and even triggers a toast when opening the project asking if you want to install the recommended extensions.