Document internationalization files in WebExtension anatomy

[MUSKANNISHAD]

This PR adds documentation for WebExtension internationalization files
by mentioning the _locales/ directory in the manifest-related file list
and introducing a short section explaining its purpose, with a link to
the Internationalization guide.

Fixes #42541

[github-actions]

Preview URLs

• /en-US/docs/Mozilla/Add-ons/WebExtensions/Anatomy_of_a_WebExtension
• /en-US/docs/Web/HTML/Reference/Elements/dialog

(comment last updated: 2026-01-09 13:28:31)

[rebloor]

@MUSKANNISHAD thanks for this. However:

• could you put the web extension and web API changes into separate PRs, as they are reviewed by different groups of people
• the changes to the anatomy of a Web extension article need to be more extensive. For example, the internationalization files are not defined within the manifest.json file. In fact, the anatomy needs to be explained more along the lines of the structure identified in the internationalization article. This then highlights other useful updates. for example, making it clear that content scripts and CSS can be referenced from both the manifest.json file and loaded arbitrary (e.g. using the scripting API).

[rebloor]

Let's keep the presentation consistent with the other sections

Suggested change

	For more details, see
	[Internationalization](/en-US/docs/Mozilla/Add-ons/WebExtensions/Internationalization).
	See [Internationalization](/en-US/docs/Mozilla/Add-ons/WebExtensions/Internationalization) to learn more to learn more.