Edit qus slightly

Author: mblue9

vignettes/tidytranscriptomics_case_study.Rmd

@@ -444,3 +444,9 @@ pbmc |>
    add_markers(size = I(1))
 
 ```
+
+## Exercises
+
+1. What proportion of of all cells are gamma-delta T cells?  
+
+2. There is a cluster of cells characterised by a low RNA output (nCount_RNA). Use tidygate to identify the cell composition (curated_cell_type) of that cluster.