Fixed typo [skip ci]

Ron Pringle · samdark · commit b21a73b910a5 · 2017-10-27T01:08:08.000+03:00
diff --git a/book/ar-single-table-inheritance.md b/book/ar-single-table-inheritance.md
@@ -175,7 +175,7 @@ are introduced just for convenience.
 The `Car` model is pretty much what was generated by Gii except additional `instantiate` method. This method is called
 after data is retrieved from database and is about to be used to initialize class properties. Return value is uninitialized
 class instance and the only argument passed to the method is the row of data retrieved from the database. Exactly what we need.
-The implementation is a simple switch statement where we're checking if the `type` field matches type of the classes we suport.
+The implementation is a simple switch statement where we're checking if the `type` field matches type of the classes we support.
 If so, an instance of the class is returned. If nothing matches, it falls back to returning a `Car` model instance. 
 
 Handling unique values
