Added global configuration page with one text box & textarea each

src/main/java/io/jenkins/plugins/sample/global_configuration/OnboardingPluginGlobalConfiguration.java

@@ -0,0 +1,28 @@
+package io.jenkins.plugins.sample.global_configuration;
+
+import hudson.Extension;
+import jenkins.model.GlobalConfiguration;
+import org.jenkinsci.Symbol;
+
+@Extension
+@Symbol("OnboardingPlugin")
+public class OnboardingPluginGlobalConfiguration extends GlobalConfiguration {
+    private String name;
+    private String description;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+}

src/main/resources/io/jenkins/plugins/sample/global_configuration/OnboardingPluginGlobalConfiguration/config.jelly

@@ -0,0 +1,11 @@
+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
+    <f:section title="Onboarding Plugin">
+        <f:entry title="${%Name}" field="name">
+            <f:textbox />
+        </f:entry>
+        <f:entry title="${%Description}" field="description">
+            <f:textarea />
+        </f:entry>
+    </f:section>
+</j:jelly>