This PR fixes the following issues in assign_lake_flag.py:
checks whether the RGI regional shapefiles are stored in a single directory, or in individual subdirectories. If neither is the case, a FileNotFoundError is raised with a message.
clarifies that "RGI v7 region name" is the full filename of the shapefile, minus the extension (e.g., RGI2000-v7.0-G-01_alaska).
This PR fixes the following issues in
assign_lake_flag.py
:FileNotFoundError
is raised with a message.