Update Documentation for cos_solar_zenith_angle Function

[Sweetdevil144]

Description

Updated the documentation for the cos_solar_zenith_angle function in the PEcAn.data.atmosphere package. The update includes detailed descriptions of function parameters, clarification of the dt and hr parameters, addition of usage examples, and an updated reference link.

Motivation and Context

This update provides clarity and useful information to users, enhancing the usability of the function.
Fixes #3084

Review Time Estimate

• Immediately
• Within one week
• When possible

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• My name is in the list of CITATION.cff
• I have updated the CHANGELOG.md.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[meetagrawal09]

I think you still have to run roxygen2::roxygenise over the package to update the Rd files based on the changes you made.

cc @infotroph, @mdietze