README: Update the JDK version 11 -> 17

README.md

@@ -4,14 +4,14 @@ This is a project template for a greenfield Java project. It's named after the J
 
 ## Setting up in Intellij
 
-Prerequisites: JDK 11, update Intellij to the most recent version.
+Prerequisites: JDK 17, update Intellij to the most recent version.
 
 1. Open Intellij (if you are not in the welcome screen, click `File` > `Close Project` to close the existing project first)
 1. Open the project into Intellij as follows:
    1. Click `Open`.
    1. Select the project directory, and click `OK`.
    1. If there are any further prompts, accept the defaults.
-1. Configure the project to use **JDK 11** (not other versions) as explained in [here](https://www.jetbrains.com/help/idea/sdk.html#set-up-jdk).<br>
+1. Configure the project to use **JDK 17** (not other versions) as explained in [here](https://www.jetbrains.com/help/idea/sdk.html#set-up-jdk).<br>
    In the same dialog, set the **Project language level** field to the `SDK default` option.
 3. After that, locate the `src/main/java/Duke.java` file, right-click it, and choose `Run Duke.main()` (if the code editor is showing compile errors, try restarting the IDE). If the setup is correct, you should see something like the below as the output:
    ```