Migrate documentation from Wiki to GitHub (#57)

* docs: migrate documentation from Jenkins Wiki to GitHub README

* docs: address review feedback

Author: 0xShubhamSolanki

README.md

@@ -1,4 +1,43 @@
-JDK Parameter Choice Plugin
-==================================
+# JDK Parameter Plugin
 
-The JDK Parameter Choice Plugin allows you to set a specific JDK to be used with a job at the start of each build.
+Adds a build parameter that allows selecting a configured JDK installation for each build.
+
+## Description
+
+This plugin adds a build parameter that allows setting which JDK should be used for a job on a per-build basis.
+
+The JDKs available for selection can be configured on the job configuration page when the JDK parameter is enabled.
+
+## Configuration
+
+1. Go to **Manage Jenkins → Global Tool Configuration**
+2. Configure one or more JDK installations
+3. Save the configuration
+
+To use in a job:
+
+1. Open the job configuration page
+2. Enable **This build is parameterized**
+3. Add parameter → Select **JDK Parameter**
+4. Choose the default JDK and allowed JDK selections
+
+## Usage
+
+On the build parameters page, a dropdown list allows selecting which configured JDK should be used for that build.
+
+## Pipeline Usage Example
+
+```groovy
+pipeline {
+    agent any
+    parameters {
+        jdk(name: 'JDK17')
+    }
+    stages {
+        stage('Check Java Version') {
+            steps {
+                sh 'java -version'
+            }
+        }
+    }
+}

pom.xml

@@ -13,7 +13,7 @@
 	<version>1.4-SNAPSHOT</version>
     <name>JDK Parameter Plugin</name>
 	<packaging>hpi</packaging>
-	<url>https://wiki.jenkins-ci.org/display/JENKINS/JDK+Parameter+Plugin</url>
+	<url>https://github.com/jenkinsci/JDK_Parameter_Plugin-plugin</url>
 
     <licenses>
         <license>