Doc: Migrate Using Kernel Threads

[lvanasse]

Migrate page Using Kernel Threads from Confluence wiki to official wiki

Summary

Migrate Using Kernel Threads to official wiki

Impact

None, just update wiki

Testing

Build doc with make autobuild

[lupyuen]

Thanks again :-)

[nuttxpr]

[Experimental Bot, please feedback here]

NuttX PR Requirements Review:

This PR appears to meet the basic NuttX requirements, but could benefit from some clarification:

✅ Summary:

• Why? Clearly states the purpose is content migration to the official wiki.
• What/How? Specifies the exact page being moved.
• Related Issues: Not applicable for content migration.

✅ Impact:

• Correctly identifies no functional changes, only documentation movement.
• However, specifying the "official wiki" URL would be helpful for reviewers.

⚠️ Testing:

• While building the documentation is a good step, it doesn't prove content accuracy.
• Ideally, manually verify the migrated page renders correctly on the new platform.
• Include links to both the old and new page locations for easy comparison.

In summary: The PR is on the right track, but bolstering the Testing section with specific verification steps and links will make it stronger.