Update release notes for rf_interpret_cell_type_as

Signed-off-by: Jason T. Brown <[email protected]>

Author: vpipkt

docs/src/main/paradox/release-notes.md

@@ -4,6 +4,7 @@
 
 ### 0.8.1
 
+* Added `rf_interpret_cell_type_as` raster function.
 * Added `toMarkdown()` and `toHTML()` extension methods for `DataFrame`, and registered them with the IPython formatter system when `rf_ipython` is imported.  
 * Fixed: Removed false return type garauntee in cases where an `Expression` accepts either `Tile` or `ProjectedRasterTile` [(#295)](https://github.com/locationtech/rasterframes/issues/295)