Update src/acquisition/covidcast/database.py

Co-authored-by: george <george.haff@gmail.com>

Author: nolangormley

src/acquisition/covidcast/database.py

@@ -563,7 +563,8 @@ def retrieve_covidcast_meta_cache(self):
     return cache_hash
 
   def compute_coverage_crossref(self):
-    """Compute coverage_crossref table."""
+    """Compute coverage_crossref table, for looking up available signals per geo or vice versa."""
+
     logger = get_structured_logger("compute_coverage_crossref")
 
     coverage_crossref_delete_sql = '''