Bug 2036647 Add use of CSS gradients to extension themes

[rebloor]

Description

Addresses the dev-docs-needed requirements of Bug 2036647 "Allow extension themes to use CSS gradients" with:

• update to the description of the theme manifest key
• a release note

Related issues and pull requests

Related browser compatibility updates in PR mdn/browser-compat-data#29910.

[github-actions]

Preview URLs (2 pages)

• /en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/theme
• /en-US/docs/Mozilla/Firefox/Releases/153

Flaws (1)

Note! 1 document with no flaws that don't need to be listed. 🎉

Found an unexpected or unresolvable flaw? Please report it here.

URL: /en-US/docs/Mozilla/Firefox/Releases/153
Title: Firefox 153 release notes for developers (Beta)
Flaw count: 1

• macros:
  • Macro domxref produces link /en-US/docs/Web/API/RTCDtlsTransport/getRemoteCertificates which doesn't resolve

External URLs (2)

URL: /en-US/docs/Mozilla/Firefox/Releases/153
Title: Firefox 153 release notes for developers (Beta)

• https://bugzil.la/1751346 (1 time) (Note! This may be a new URL 👀)
• https://bugzil.la/2036647 (1 time) (Note! This may be a new URL 👀)

(comment last updated: 2026-06-29 19:15:13)

[github-actions]

This pull request has merge conflicts that must be resolved before it can be merged.