Fix gsp subproject readme as it is not a Gradle plugin

Author: bobbywarner

grails-gsp/README.md

@@ -1,12 +1,12 @@
-## Grails GSP Gradle Plugin 
+## Grails GSP
 
-This gradle plugin is required for all grails 3 applications and plugins that require GSP processing.  If your project includes GSPs you should add the following to your `build.gradle`.
+This subproject is required for all Grails 3 applications and plugins that require GSP processing.  If your project includes GSPs you should add the following to your `build.gradle` which is provided by the [Grails Gradle Plugin](https://github.com/grails/grails-core/tree/master/grails-gradle-plugin).
 
 ``` gradle
 apply plugin: "org.grails.grails-gsp"
 ```
 
-It is typical of standard grails 3 application to use this in conjunction with `grails-web` as in the following example: 
+It is typical of standard Grails 3 application to use this in conjunction with `grails-web` as in the following example:
 
 ``` gradle
 apply plugin: "org.grails.grails-web"
@@ -15,4 +15,4 @@ apply plugin: "org.grails.grails-gsp"
 
 Dependencies
 -----
-To see what additional plugins will be included with this plugin you can view this project's [build.gradle](https://github.com/grails/grails-core/blob/master/grails-gsp/build.gradle)
+To see what additional subprojects will be included with this, you can view this project's [build.gradle](https://github.com/grails/grails-core/blob/master/grails-gsp/build.gradle)