Update instructions.md

Fix terminology for PowerBI

Author: carlos-esquivel-gs

data/covid/instructions.md

@@ -17,7 +17,7 @@ You should provide a report with two pages:
     4. A graph showing the cases trend in months
     5. A graph showing the deaths trend in months
     6. Treemap of countries ordered by deaths
-* A report view showing the cases and deaths by month with filtering and drill-down capabilities (free design)
+* A report view showing the cases and deaths by month with filtering and drill-through capabilities (free design)
 
 ### Filters
 You should allow the following filters:
@@ -29,4 +29,4 @@ You should allow the following filters:
 
 Extra bonus points (require external data)
 1. Showing the cases and deaths normalized over the country' population
-2. Source vaccine progress data and integrate it in the report
+2. Source vaccine progress data and integrate it in the report