docs: allow `symbolic_evaluate` to have arbitrary kwargs

[AayushSabharwal]

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

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 33.13%. Comparing base (584bf3d) to head (d276ade).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #61 +/- ## ======================================= Coverage 33.13% 33.13% ======================================= Files 7 7 Lines 341 341 ======================================= Hits 113 113 Misses 228 228 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.