Add documentation to InstallExtension

src/main/groovy/io/openliberty/tools/gradle/extensions/InstallExtension.groovy

@@ -1,5 +1,5 @@
 /**
- * (C) Copyright IBM Corporation 2014, 2019.
+ * (C) Copyright IBM Corporation 2014, 2025.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,12 +17,36 @@ package io.openliberty.tools.gradle.extensions
 
 class InstallExtension {
 
+    // WebSphere Liberty server license code. See [installLiberty task](installLiberty.md#installliberty-task).
     String licenseCode
+
+    // Exact or wildcard version of the WebSphere Liberty server to install. 
+    // Available versions are listed in the [index.yml](http://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/wasdev/downloads/wlp/index.yml) file. 
+    // Only used if `runtimeUrl` is not set and `libertyRuntime` is not configured. By default, the latest stable release is used. 
     String version
+
+    // URL to the WebSphere Liberty server's `.jar` or a `.zip` file on your repository or on the [Liberty repository](https://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/wasdev/downloads/wlp/). 
+    // `runtimeUrl` can also point to an [Open Liberty](https://public.dhe.ibm.com/ibmdl/export/pub/software/openliberty/runtime/release/) `.zip`. 
+    // If not set and `libertyRuntime` is not configured, the Liberty repository will be used to find the Liberty runtime archive. 
     String runtimeUrl
+
+    // Username needed for basic authentication. 
     String username
+
+    // Password needed for basic authentication.
     String password
+
+    // Maximum time in seconds the download can take. The default value is `0` (no maximum time).
     String maxDownloadTime
+
+    // Liberty runtime type to download from the Liberty repository. 
+    // Currently, the following types are supported: `kernel`, `webProfile6`, `webProfile7`, `webProfile8`, `javaee7`, and `javaee8`. 
+    // Only used if `runtimeUrl` is not set and `libertyRuntime` is not configured. 
+    // The default value is `webProfile7` if `useOpenLiberty` is `false`. 
+    // If using Open Liberty and no type is specified, the default Open Liberty runtime is used.
     String type
+
+    // Specifies whether to install Open Liberty or WebSphere Liberty runtime when `runtimeUrl` is not specified and `libertyRuntime` is not configured. 
+    // The default value is `true`.
     String useOpenLiberty
 }