CloseWatcher - minor subedit and live example

[hamishwillee]

FF321 supports CloseWatcher in https://bugzilla.mozilla.org/show_bug.cgi?id=1888729 behind the pref dom.closewatcher.enabled.

This restructures the introduction, adding more information and pushing most of it into the description. It also adds a live example. The example doesn't add much (if any) new information, but it is more "real" than the succinct example that precedes it.

Related docs work can be tracked in #36126

[github-actions[bot]]

Preview URLs

• /en-US/docs/Web/API/CloseWatcher

(comment last updated: 2024-10-20 20:26:40)

[hamishwillee]

Thanks for the review @sideshowbarker