fix: small clarification in exercise text

sessions/data-management.qmd

@@ -460,7 +460,8 @@ We can now "read" these actions as:
 
 > Time: 10 minutes.
 
-In the `R/learning.R` script file, complete the following tasks.
+In the `R/learning.R` script file, complete the following tasks, running
+each code after completing the task.
 
 1.  Copy and paste the code below into the script file. Replace the
     `___` in the `select()` function, with the columns `bp_sys_ave`, and
@@ -1089,3 +1090,4 @@ files into R.
     package to wrangle your data.
 -   Use the pipe (`%>%`) to write easy-to-read code, similar to reading
     a text consisting of multiple sentences.
+