doc: update example page help text

Remove out-of-date references to manifest.yaml and improve the help text
on the example page.

src/components/ExamplePage.tsx

@@ -5,7 +5,6 @@ import {
   PageSection,
   Text,
   TextContent,
-  TextVariants,
   Title,
 } from '@patternfly/react-core';
 
@@ -21,18 +20,22 @@ export default function ExamplePage() {
         </PageSection>
         <PageSection variant="light">
           <TextContent>
-            <Text component={TextVariants.p}>
-              This is a custom page contributed by the template console plugin.
+            <Text component="p">
+              Nice! Your plugin is working.
+            </Text>
+            <Text component="p">
+              This is a custom page contributed by the console plugin template.
               The extension that adds the page is declared in
-              console-extensions.json in the package root along with the
+              console-extensions.json in the project root along with the
               corresponding nav item. Update console-extensions.json to change
-              or add extensions.
+              or add extensions. Code references in console-extensions.json
+              must have a corresonding property <code>exposedModules</code> in
+              package.json mapping the reference to the module.
             </Text>
-            <Text component={TextVariants.p}>
+            <Text component="p">
               After cloning this project, replace references to
               <code>console-template-plugin</code> and other plugin metadata in
-              the <code>package.json</code> and <code>manifest.yaml</code>
-              files with values for your plugin.
+              <code>package.json</code> with values for your plugin.
             </Text>
           </TextContent>
         </PageSection>