Cleanup documentation

The ModelingToolkitStandardLibrary docs could use a cleanup.

I have spotted the following issues, but there are probably more:

• Several places have missing docstrings. Either these components have been deleted or there are indeed actually missing docstrings. For example, see Digital-Gates
• For some components the description is not formatted correctly, for example: Electrical.PNP
• A different problem with parameters exists here: Electrical.VariableResistor
• For several components the references are missing, for example: Mechanical.Translational.AccelerationSensor is missing references to Flange and RealOutput
• The CI for code formatting is not passing: https://github.com/SciML/ModelingToolkitStandardLibrary.jl/actions/runs/16293870067/job/46010188959

Plenty of QOL and other improvements are also possible and would benefit the documentation.

@ChrisRackauckas this seems like an issue Claude could handle. I have no problem reviewing it, but I don't know how that would work given I have no rights or anything.

Start with the linked API pages for Digital-Gates, Electrical.PNP, Electrical.VariableResistor, and Mechanical.Translational.AccelerationSensor, then inspect the corresponding documentation and docstrings. Run the linked code-formatting CI job to identify formatting failures. Done means the cited missing docstrings, descriptions, parameters, references, and formatting issues are corrected, with any additional cleanup clearly scoped.