add some client download link and fix readme

[Gaobaiawa]

Description

Please carefully read the Contributing note and Code of conduct before making any pull requests.

Issues fixed by this PR

Type of changes

• [ ] Bug fix
• [ ] New feature
• [ ] Enhancement
• [x] Documentation

Checklist:

• [x] My code follows the style guidelines of this project
• [x] My pull request is unique and no other pull requests have been opened for these changes
• [x] I have read the Contributing note and Code of conduct
• [x] I am responsible for any copyright issues with my code if it occurs in the future.