docs: add knowledge base set up instruction to Readme file

[JackYPCOnline]

Description

[Provide a detailed description of the changes in this PR]
add knowledge base set up instruction to Readme file

Related Issues

[Link to related issues using #issue-number format]

Documentation PR

[Link to related associated PR in the agent-docs repo]

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Other (please describe):

[Choose one of the above types of changes]

Testing

[How have you tested the change?]

• hatch fmt --linter
• hatch fmt --formatter
• hatch test --all

Checklist

• I have read the CONTRIBUTING document
• I have added tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature
• My changes generate no new warnings
• Any dependent changes have been merged and published

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.