Fix docstring refrences optfun and optprob

[Vaibhavdixit02]

Checklist

• [ ] Appropriate tests were added
• [ ] Any code changes were done in a way that does not break public API
• [ ] All documentation related to code changes were updated
• [ ] The new code follows the contributor guidelines, in particular the SciML Style Guide and COLPRAC.
• [ ] Any new documentation only uses public API

Additional context

Add any other context about the problem here.

[codecov[bot]]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (0d26722) 5.27% compared to head (c0a239c) 26.38%.

Files	Patch %	Lines
src/scimlfunctions.jl	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #564 +/- ## =========================================== + Coverage 5.27% 26.38% +21.10% =========================================== Files 53 53 Lines 4058 4086 +28 =========================================== + Hits 214 1078 +864 + Misses 3844 3008 -836 ```

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