update docs

Signed-off-by: Nshawn_he <shawn.he@huawei.com>

en/application-dev/reference/apis/js-apis-intl.md

@@ -388,7 +388,7 @@ Provides the device capability.
 | currencyDisplay          | string  | Yes   | Yes   | Currency display mode. The value can be **symbol**, **narrowSymbol**, **code**, or **name**.|
 | unit                     | string  | Yes   | Yes   | Unit name, for example, **meter**, **inch**, or **hectare**.       |
 | unitDisplay              | string  | Yes   | Yes   | Unit display format. The value can be **long**, **short**, or **medium**.|
-| unitUsage                | string  | Yes   | Yes   | Unit usage scenario. The value can be any of the following: **default**, **area-land-agricult**, **area-land-commercl**, **area-land-residntl**, **length-person**, **length-person-small**, **length-rainfall**, **length-road**, **length-road-small**, **length-snowfall**, **length-vehicle**, **length-visiblty**, **length-visiblty-small**, **length-person-informal**, **length-person-small-informal**, **length-road-informal**, **speed-road-travel**, **speed-wind**, **temperature-person**, **temperature-weather**, **volume-vehicle-fuel**.|
+| unitUsage<sup>8+</sup>                | string  | Yes   | Yes   | Unit usage scenario. The value can be any of the following: **default**, **area-land-agricult**, **area-land-commercl**, **area-land-residntl**, **length-person**, **length-person-small**, **length-rainfall**, **length-road**, **length-road-small**, **length-snowfall**, **length-vehicle**, **length-visiblty**, **length-visiblty-small**, **length-person-informal**, **length-person-small-informal**, **length-road-informal**, **speed-road-travel**, **speed-wind**, **temperature-person**, **temperature-weather**, **volume-vehicle-fuel**.|
 | signDisplay              | string  | Yes   | Yes   | Number sign display format. The value can be **auto**, **never**, **always**, or **expectZero**.|
 | compactDisplay           | string  | Yes   | Yes   | Compact display format. The value can be **long** or **short**.     |
 | notation                 | string  | Yes   | Yes   | Number formatting specification. The value can be **standard**, **scientific**, **engineering**, or **compact**.|