update doc

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

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

@@ -3,6 +3,7 @@
 The Keycode module provides keycodes for a key device.
 
 > **NOTE**
+> 
 > The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
 
 ## Modules to Import
@@ -337,7 +338,7 @@ import {KeyCode} from '@ohos.multimodalInput.keyCode';
 | KEYCODE_WWAN_WIMAX               |  2846 | WWAN WiMAX key               |
 | KEYCODE_RFKILL                   |  2847 | RF Kill key                  |
 | KEYCODE_CHANNEL                  |  3001 | Channel key                      |
-| KEYCODE_BTN_0                    |  3100 | Key 0                        |
+| KEYCODE_BTN_0                    |  3100 | Button 0                        |
 | KEYCODE_BTN_1                    |  3101 | Button 1                        |
 | KEYCODE_BTN_2                    |  3102 | Button 2                        |
 | KEYCODE_BTN_3                    |  3103 | Button 3                        |