Download as Python script / separate section for Application Scripts

[ahuang11]

Right now, users must use notebooks to run through the example, but not as vanilla Python scripts.

However, because cookbooks are instructional walkthroughs, it may not make sense to have a download button to run the example.

Instead, I think I'm leaning towards having a separate section for Application Scripts for users to browse, copy/paste, and modify a bit to use.

For example, when I was still using NCL, this was a page I visited often: https://www.ncl.ucar.edu/Applications/