Fix typo

Author: spebon

_posts/03-06-01-XDebug.md

@@ -34,7 +34,7 @@ Your IDE will now intercept the current state as the script executes, allowing y
 values in memory.
 
 Graphical debuggers make it very easy to step through code, inspect variables, and eval code against the live runtime.
-Many IDE's have built-in or plugin-based support for graphical debugging with Xdebug. MacGDBp is a free, open-source,
+Many IDEs have built-in or plugin-based support for graphical debugging with Xdebug. MacGDBp is a free, open-source,
 stand-alone Xdebug GUI for Mac.
 
  * [Learn more about Xdebug][xdebug-docs]