update en/release-notes/Readme.md.

Signed-off-by: Nduangavin123 <duanxichao@huawei.com>

en/release-notes/Readme.md

 # OpenHarmony Release Notes
 ## OpenHarmony 2.x Releases
--   [OpenHarmony 2.2 vBeta2 (2021-08-04)](OpenHarmony-v2.2-beta2.md)
+-   [OpenHarmony v2.2 beta2 (2021-08-04)](OpenHarmony-v2.2-beta2.md)
 -   [OpenHarmony 2.0 Canary (2021-06-02)](openharmony-2-0-canary.md)
 ## OpenHarmony 1.x Releases
--   [OpenHarmony 1.1.2 LTS (2021-08-04)](OpenHarmony-1-1-2-LTS.md)
+-   [OpenHarmony v1.1.2 LTS (2021-08-04)](OpenHarmony-v1.1.2-LTS.md)
 -   [OpenHarmony 1.1.1 LTS (2021-06-22)](OpenHarmony-1-1-1-LTS.md)
 -   [OpenHarmony 1.1.0 LTS (2021-04-01)](openharmony-1-1-0-lts.md)
 -   [OpenHarmony 1.0 (2020-09-10)](OpenHarmony-1-0.md)