[cleanup] Removes PageIndex service

This snuck in in the last PR, I originally implemented the
page index as a service but realized it wasn't necessary
in the end

Author: pzuraq

addon/components/docs-viewer/x-main/component.js

@@ -21,7 +21,6 @@ export default Component.extend({
 
   router: service(),
   docsRoutes: service(),
-  pageIndex: service(),
 
   tagName: 'main',
   classNames: ['lg:w-4/5', 'xl:w-3/5', 'max-w-md', 'lg:max-w-none', 'mx-auto', 'lg:mx-0', 'mt-6', 'flex-no-shrink'],

addon/components/docs-viewer/x-page-index/component.js

@@ -1,5 +1,4 @@
 import Component from '@ember/component';
-import { inject as service } from '@ember/service';
 import layout from './template';
 
 export default Component.extend({
@@ -8,5 +7,4 @@ export default Component.extend({
 
   tagName: '',
 
-  pageIndex: service()
 });