[Documentation] Document the configuration of Project JDK and Maven J…

…DK in IntelliJ (apache#10371)

* Document the configuration of Project JDK and Maven JDK in IntelliJ

* Rephrase wording for choosing the JDK

* Update site2/website/contributing.md

Co-authored-by: Yu Liu <[email protected]>

* Update README.md

Co-authored-by: Yu Liu <[email protected]>

* Update README.md

Co-authored-by: Yu Liu <[email protected]>

* Update README.md

Co-authored-by: Huanli Meng <[email protected]>

* Address review feedback about using bold style for buttons instead of code style

Co-authored-by: Yu Liu <[email protected]>
Co-authored-by: Huanli Meng <[email protected]>

README.md

@@ -136,21 +136,45 @@ required plugins.
 
 ### Intellij
 
+#### Configure Project JDK to Java 8 (1.8) JDK
+
+1. Open **Project Settings**. 
+
+    Click **File** -> **Project Structure** -> **Project Settings** -> **Project**.
+
+2. Select the JDK version.
+
+    From the JDK version drop-down list, select **Download JDK...** or choose an existing recent Java 8 (1.8) JDK version.
+
+3. In the download dialog, select version **1.8**. You can pick a version from many vendors. Unless you have a specific preference, choose **AdoptOpenJDK (Hotspot)**.
+
+
+#### Configure Java version for Maven in IntelliJ
+
+1. Open Maven Importing Settings dialog by going to 
+   **Settings** -> **Build, Execution, Deployment** -> **Build Tools** -> **Maven** -> **Importing**.
+
+2. Choose **Use Project JDK** for **JDK for Importer** setting. This uses the Java 8 (1.8) JDK for running Maven 
+   when importing the project to IntelliJ. Some of the configuration in the Maven build is conditional based on 
+   the JDK version. Incorrect configuration gets chosen when the "JDK for Importer" isn't the same as the "Project JDK".
+
+3. Validate that the JRE setting in **Maven** -> **Runner** dialog is set to **Use Project JDK**.
+
 #### Configure annotation processing in IntelliJ
 
 1. Open Annotation Processors Settings dialog box by going to
-   `Settings -> Build, Execution, Deployment -> Compiler -> Annotation Processors`.
+   **Settings** -> **Build, Execution, Deployment** -> **Compiler** -> **Annotation Processors**.
 
 2. Select the following buttons:
-   1. "Enable annotation processing"
-   2. "Obtain processors from project classpath"
-   3. "Store generated sources relative to: Module content root"
+   1. **Enable annotation processing**
+   2. **Obtain processors from project classpath**
+   3. Store generated sources relative to: **Module content root**
 
 3. Set the generated source directories to be equal to the Maven directories:
    1. Set "Production sources directory:" to "target/generated-sources/annotations".
    2. Set "Test sources directory:" to "target/generated-test-sources/test-annotations".
 
-4. Click "OK".
+4. Click **OK**.
 
 5. Install the lombok plugin in intellij.
 

site2/website/contributing.md

@@ -118,43 +118,10 @@ these two remotes for pushing changes).
 
 You are now ready to start developing!
 
-#### [Optional] IDE Setup
+#### IDE Setup
 
-Depending on your preferred development environment, you may need to prepare it to develop Pulsar code.
+For how to set up IDE, see [here](https://github.com/apache/pulsar/blob/master/README.md#setting-up-your-ide). 
 
-##### IntelliJ
-
-###### Enable Annotation Processing
-
-To configure annotation processing in IntelliJ:
-
-1. Open Annotation Processors Settings dialog box by going to Settings -> Build, Execution, Deployment -> Compiler -> Annotation Processors.
-1. Select the following buttons:
-    1. "Enable annotation processing"
-    1. "Obtain processors from project classpath"
-    1. "Store generated sources relative to: Module content root"
-1. Set the generated source directories to be equal to the Maven directories:
-    1. Set "Production sources directory:" to "target/generated-sources/annotations".
-    1. Set "Test sources directory:" to "target/generated-test-sources/test-annotations".
-1. Click "OK".
-
-##### Eclipse
-
-Use a recent Eclipse version that includes m2e. Start Eclipse with a fresh workspace in a
-separate directory from your checkout.
-
-###### Initial setup
-
-1. Import the Pulsar projects
-
-	File
-	-> Import...
-	-> Existing Maven Projects
-	-> Browse to the directory you cloned into and select "pulsar"
-	-> make sure all pulsar projects are selected
-	-> Finalize
-
-You now should have all the Pulsar projects imported into eclipse and should see no compile errors.
 
 ### Create a branch in your fork