Improve "deprecated_badge_title" message

### MDN URL

https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest/RuleCondition

### What specific section or headline is this issue about?

_No response_

### What information was incorrect, unhelpful, or incomplete?

N.B. MDN page is given as an example only.

```html

Deprecated

```

`{{deprecated_inline}}` message (i.e. "websites") in not best suited under: [Mozilla](https://developer.mozilla.org/en-US/docs/Mozilla) > [Add-ons](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons) > [Browser extensions](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions) > [JavaScript APIs](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API)

https://github.com/mdn/content/blob/63dd9b763192e1aa40b75c04b0c3aa53d8cb974a/files/jsondata/L10n-Template.json#L28-L34

### What did you expect to see?

A general-purpose message (for both Web API and Extension API) e.g.
"Deprecated. Not for use in future developments."

### Do you have any supporting links, references, or citations?

_No response_

### Do you have anything more you want to share?

_No response_

### MDN metadata

Page report details

* Folder: `en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rulecondition`
* MDN URL: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest/RuleCondition
* GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/mozilla/add-ons/webextensions/api/declarativenetrequest/rulecondition/index.md
* Last commit: https://github.com/mdn/content/commit/c01b393fbb6939f88cc98ac2a34df1a54be1edfd
* Document last modified: 2025-04-30T00:14:24.000Z