Main Stylesheet doc page is missing Update URI

[waviaei]

Issue Description

Theme handbook's main stylesheet doc is missing "Update URI" theme header that was introduced in 6.1
https://make.wordpress.org/core/2022/10/06/introducing-update-uri-theme-header-in-wordpress-6-1/

URL of the Page with the Issue

https://developer.wordpress.org/themes/core-concepts/main-stylesheet/

Section of Page with the issue

Header Fields. Or, create a new section at the bottom

Why is this a problem?

Not up to date with the latest theme header spec.

Suggested Fix

Update Header Fields section by adding Theme URI to the example code and description.

[github-actions]

Heads up @WordPress/docs-issues-coordinators, we have a new issue open. Time to use 'em labels.