add some project structure language in the readme

Author: CarlyLanglois

README.md

@@ -9,6 +9,17 @@ course.
 The classes in this repo require Java11. Please refer to the book referenced
 above for instructions on how to download and use the examples.
 
+To update this Project's SDK to use Java11 on your computer: 
+
+- Go to *File -> Project Structure*
+- Under *Project Settings*, select *Project*
+- Under *Project SDK*, select your downloaded Java 11 JDK.
+    - Note: You may also download the JDK directly from your menu options here.
+    
+- Next, under *Platform Settings*, select *SDKs* and again select Java11.
+- Once selected, hit *Apply* and *Ok*
+    
+
 ## Updating
 
 Occasionally, the LaunchCode team will make changes to this repository