fix typo

Author: jdaugherty

README.md

@@ -112,7 +112,7 @@ For further information, please consult the [documentation](https://docs.grails.
 
 For detailed building Grails, please consult the [CONTRIBUTING.md](CONTRIBUTING.md) file. To bootstrap the project from a source distribution, you can execute: 
 
-    cd gralde-bootstrap
+    cd gradle-bootstrap
     gradle wrapper
 
 Then you can proceed with running any valid gradle command from [CONTRIBUTING.md](CONTRIBUTING.md).