Revise tutorial access information for NSIDC DAAC data

Update README to reflect changes in data access method

Author: mikala-nsidc

README.md

@@ -52,6 +52,7 @@ Originally demonstrated through the NASA Earthdata Webinar "Let It Snow! Accessi
 
 > [!WARNING]  
 > Data access is no longer possible using the method described in this tutorial, because of the migration of data to the NASA Earthdata Cloud environment.
+
 Originally presented during the 2019 AGU Fall Meeting, this tutorial demonstrates the NSIDC DAAC's data discovery, access, and subsetting services, along with basic open source resources used to harmonize and analyze data across multiple products. The tutorial is provided as a series of Python-based Jupyter Notebooks, focusing on sea ice height and ice surface temperature data from NASA’s ICESat-2 and MODIS missions, respectively, to characterize Arctic sea ice.  
 
 ### [SMAP](./notebooks/SMAP)