Add user guide or frequently asked questions to Permafrost Discovery Gateway after new features are added

[julietcohen]

It would be helpful to add some sort of user guide or FAQ portion to the PDG webpage to encourage researchers and educators to use the portal in the way that works best for them. This will be especially useful when we add new features to the user interface such as drawing a bounding box to visualize data from that region as a plot.

The user guide(s) would explain:

1. how to use/interpret the Imagery Viewer or Fluid Earth Viewer if we get feedback that users find toggling layers and temperature/precipitation to be confusing
2. draw a bounding box, toggle between parameters or datasets in the plots
3. the pros and cons of drawing larger or smaller boxes, if that ends up determining the resolution of the visualized data
4. how to navigate to a dataset's ADC package to download data, view the metadata, and download the model if that is archived as well

The user guide(s) could take the form of:

• a short video with voice over
• a static document or bookdown with inserted screenshots
• an FAQ page
• a use case example, like a start-to-finish short analysis in Python or R where a user downloads a subset of one or two datasets from a region of interest, does initial exploration of the variables outside of the UI, and makes a figure or map that is interesting / shows trends that can be used in the classroom or a scientific paper

See here for an example a user guide for another interactive portal: the Climate Mapping for Resilience and Adaptation. They use a static page with screenshots.