Fix the example jsdoc config in README.md

[maxime-bc]

Description

Fixes #103 : in the jsdoc config example of the README, the markdown object is a child of the opts object.

The use of this jsdoc configuration causes links inside the "On this page" section referring to the README content to not work properly.

As seen inside the file jsdoc-config.json, the markdown object should be a child of the root object.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Other (if so, then explain below briefly)

[github-actions]

That's Amazing! Thanks for creating your first PR for clean-jsdoc-theme. Someone will review it soon!

[ankitskvmdam]

Thanks for the PR!