### Describe the bug The help documentation for PVWatts includes a link to a description of the physical model for IAM. The link is: https://pvpmc.sandia.gov/modeling-steps/1-weather-design-inputs/shading-soiling-and-reflection-losses/incident-angle-reflection-losses/physical-model-of-iam/ which does not work. I think it should be: https://pvpmc.sandia.gov/modeling-steps/1-weather-design-inputs/shading-soiling-and-reflection-losses/incident-angle-reflection-losses/physical-iam-model/ ### Screenshots <img width="613" alt="image" src="https://github.com/NREL/SAM/assets/45701090/e1e9321c-d665-4854-a901-c6ef30a776d9"> 
Describe the bug
The help documentation for PVWatts includes a link to a description of the physical model for IAM. The link is:
https://pvpmc.sandia.gov/modeling-steps/1-weather-design-inputs/shading-soiling-and-reflection-losses/incident-angle-reflection-losses/physical-model-of-iam/
which does not work. I think it should be:
https://pvpmc.sandia.gov/modeling-steps/1-weather-design-inputs/shading-soiling-and-reflection-losses/incident-angle-reflection-losses/physical-iam-model/
Screenshots