to_16_point optimization in metno.py file

[ManchurianMan]

Updated to_16_point function in metno.py

Changes:

Improved readability and efficiency.
Added a docstring explaining the input and output of the function.

Comparison:

Accuracy: Verified against the original function across all 360 degrees (both integers and floats). Outputs match.

Speed: Tested using the timeit module at 1,000,000 iterations:

• to_16_point_v1: 0.13851 seconds
• to_16_point_v2: 0.12557 seconds

Motivation:

I'm contributing to open source to give back to the community. This change, while small, is a step towards improving wttr.in. Feedback is appreciated!