typo in 172 line

had fix small typo in 172 line

Author: dandgerson

2-ui/3-event-details/3-mousemove-mouseover-mouseout-mouseenter-mouseleave/article.md

@@ -169,7 +169,7 @@ Here's the full example with all details:
 
 [codetabs height=380 src="mouseenter-mouseleave-delegation-2"]
 
-Try to move the cursor in and out of table cells and inside them. Fast or slow -- doesn't better. Only `<td>` as a whole is highlighted unlike the example before.
+Try to move the cursor in and out of table cells and inside them. Fast or slow -- doesn't matter. Only `<td>` as a whole is highlighted unlike the example before.
 ```