hayleyling

The readme file needs to be updated as there are some language errors and inaccurate descriptions.

Update the readme file: 1. Correct some language errors and inaccurate descriptions. 2. Add icons to make it more user-friendly.

### What type of PR is this? doc ### Which issue(s) this PR fixes? 1. Translate manage_mysql_user.md. 2. Change file name from mgt_mysqlusser to manage_mysql_user.md for both Chinese and English...

1. Translate the newly created Chinese docs. 2. Update and proofread docs.

doc: update readme #161

1

1. Correct some minor errors in the readme file. 2. Add icons to make it more readable.

Some mirror errors in the readme file needs to be corrected.