Use NWS info pages to derive local settings

[jessehamner]

It's possible to use several web API calls (with JSON returns) to determine many abbreviations, location identifiers, and settings that are currently entered by hand in settings.yml. The script should provide a one-time or on-demand functionality to retrieve as many of these settings as possible to simplify setup.
Many locally applicable settings are contained in these API URLS:

• https://api.weather.gov/points/2-decimal-LAT,2-decimal-LON
• https://api.weather.gov/gridpoints/

See especially

• Local observation stations: https://api.weather.gov/gridpoints/FWD/78,120/stations
• Hourly forecast by grid coords: https://api.weather.gov/gridpoints/FWD/78,120/forecast/hourly

[jessehamner]

Started work. Have implemented "points" and "stations", and written results to a test YAML file. Need to conform names to existing variable names. Should enable simpler and more robust code.

[jessehamner]

Relevant pages on NWS API and XML schema:

• https://preview.weather.gov/xml/schema/DWML.xsd
• https://preview.weather.gov/xml/
• https://www.weather.gov/documentation/services-web-api

[jessehamner]

Have conformed NWS variable names to existing YAML variable names. Need to create a separate configuration command-line option to avoid configuring the settings.yml file every time.