Remove unneeded characters

[DevLab2425]

Purpose (TL;DR) - mandatory

Clean up Spies documentation to remove unnecessary characters (]}]}) within the spyCall.returnValue description.

Background (Problem in detail) - optional

Extra characters are included within the spyCall.returnValue description text.

Solution - optional

Removed the extra characters.

How to verify - mandatory

1. Check out this branch
2. npm install
3. Follow the Running the documentation site locally steps within the CONTRIBUTING.md file
4. Navigate to the Spies documentation
5. Scroll to the spyCall.returnValue description (last one on the page)
6. Confirm the description simply says "Return value" and NOT "Return value.]}]}"

Checklist for author

• npm run lint passes
• References to standard library functions are cached.

[mroderick]

Thank you ❤️