Update README.md

Picky spelling fix.

Author: sammcd

README.md

@@ -193,7 +193,7 @@ Common Problems
 
 ### Using dynamic image size with UITableViewCell
 
-UITableView determins the size of the image by the first image set for a cell. If your remote images
+UITableView determines the size of the image by the first image set for a cell. If your remote images
 don't have the same size as your placeholder image, you may experience strange anamorphic scaling issue.
 The following article gives a way to workaround this issue: