There is a [`./icons/preview.html`](./icons/preview.html) file that can be opened to see all of the icons included in the theme.
To view this, it needs to be hosted by a web server. The easiest way is to open the file with the `Open with Live Server` command from the [Live Server extension](https://marketplace.visualstudio.com/items?itemName=ritwickdey.LiveServer).
- have the main branches of `https://github.com/jesseweed/seti-ui` and `https://github.com/microsoft/vscode` cloned in the same parent folder
- in the `seti-ui` folder, run `npm install` and `npm run prepublishOnly`. This will generate updated icons and fonts.
- in the `vscode/extensions/theme-seti` folder run `npm run update`. This will launch the [icon theme update script](build/update-icon-theme.js) that updates the theme as well as the font based on content in `seti-ui`.
- to test the icon theme, look at the icon preview as described above.
- when done, create a PR with the changes in https://github.com/microsoft/vscode.
Add a screenshot of the preview page to accompany it.