doc: correct desc in README.md

[zhongjiajie]

Brief Summary of The Change

correct the docs in readme

Pull Request checklist

I confirm that the following checklist has been completed.

• [x] Add/Change test cases for the changes.
• [x] Add/Change the related documentation, should also change docs/source/config.rst when you change file default_config.yaml.
• [ ] (Optional) Add your change to UPDATING.md when it is an incompatible change.

[codecov-commenter]

Codecov Report

Merging #105 (ab0af26) into main (a2fe58b) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #105   +/-   ##
=======================================
  Coverage   90.75%   90.75%           
=======================================
  Files          63       63           
  Lines        2314     2314           
=======================================
  Hits         2100     2100           
  Misses        214      214           

Flag	Coverage Δ
unittests	90.75% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more