README: README optimize

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4FS3G?from=project-issue


CVE: NA

---------------------------

There are some language problems in the README file, and MarkDown fromat
syntax is not effective, and it needs to be adjusted.

Signed-off-by: suqin <suqin2@huawei.com>
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>