Fix typo in header docs: s/interects/intersects/

[jcdyer]

Please do not open a pull request without first filing an issue and/or discussing the feature directly with me.

Please ensure you adhere to every item in this list

This is not a feature. I don't believe it needs pre-approval.

• [ ] This PR was pre-approved by the project maintainer
• [x] I have self-reviewed the code
• [x] I have added all necessary tests

Describe your changes

The docs in the header file include a code typo, where the tg_geom_intersects function is missing the first s

Issue number and link

N/A. The fix is the bug report.

[tidwall]

Thanks!