Fix typo in 'Slicing Subsets of Rows and Columns in Python.' Change syntax slightly for conciseness.

Fixed the typo "That is, YOUR specify rows and columns giving a number."
Updated "giving" to "using" in above phrase.

Author: lannzach-sul

episodes/03-index-slice-subset.md

@@ -313,8 +313,8 @@ surveys_df = pd.read_csv("data/surveys.csv")
 We can select specific ranges of our data in both the row and column directions
 using either label or integer-based indexing.
 
-- `iloc` is primarily an *integer* based indexing counting from 0. That is, your
-  specify rows and columns giving a number. Thus, the first row is row 0,
+- `iloc` is primarily an *integer* based indexing counting from 0. That is, you
+  specify rows and columns using a number. Thus, the first row is row 0,
   the second column is column 1, etc.
 
 - `loc` is primarily a *label* based indexing where you can refer to rows and