[doc] Add R tab to parameter tuning tutorial

[sansha521]

Summary

• Add R tabs alongside the Python examples in the parameter tuning tutorial.
• Add base R examples for the memory usage recommendations.
• Avoid introducing additional R package dependencies.

Testing

• Built the documentation locally with make html.
• Verified the Python and R tabs render correctly in the parameter tuning tutorial.

Closes #12501.

Part of #11413.