Change Exercise to Discussion line 91

_episodes/01-tidiness.md

@@ -88,7 +88,7 @@ analysis you want to do, you may even separate the genus and species names into
 
 [![Messy spreadsheet](../fig/01_tidiness_datasheet_example_messy.png)](https://github.com/datacarpentry/organization-genomics/raw/gh-pages/files/Ecoli_metadata_composite_messy.xlsx)
 
-> ## Exercise
+> ## Discussion
 > This is some potential spreadsheet data generated about a sequencing experiment. With the person next to you, for about 2 minutes, discuss some of the problems with the spreadsheet data shown above. You can look at the image, or download the file to you computer via this [link](https://github.com/datacarpentry/organization-genomics/raw/gh-pages/files/Ecoli_metadata_composite_messy.xlsx) and open it in a spreadsheet reader like Excel. 
 >
 >