Address review feedback on plugin README updates

- Apply freben's suggested wording for old frontend system sections to
  clarify they can be skipped on the new frontend system
- Fix scaffolder README: add missing imports (AnyApiFactory,
  scmIntegrationsApiRef), closing bracket, and update link text
- Fix devtools README: correct closing tag from `</ FlatRoutes>` to
  `</FlatRoutes>`
- Fix kubernetes README: reword "must be explicitly added" to avoid
  conflicting with feature discovery paragraph

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

plugins/api-docs/README.md

@@ -342,7 +342,7 @@ import { ApiExplorerPage } from '@backstage/plugin-api-docs';
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 1. Add the `ApiExplorerPage` extension to the app:
 

plugins/catalog-graph/README.md

@@ -143,7 +143,7 @@ import {
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 1. Add the `CatalogGraphPage` to your `packages/app/src/App.tsx`:
 

plugins/catalog/README.md

@@ -24,7 +24,7 @@ Once installed, the plugin is automatically available in your app through the de
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 ### Add the plugin to your `packages/app`
 

plugins/devtools/README.md

@@ -202,7 +202,7 @@ Here's how to add the Catalog Unprocessed Entities tab:
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 1. Open the `packages/app/src/App.tsx` file
 2. Then after all the import statements add the following line:
@@ -211,7 +211,7 @@ If your Backstage app uses the old frontend system, you need to manually wire th
    import { DevToolsPage } from '@backstage/plugin-devtools';
    ```
 
-3. In this same file just before the closing `</ FlatRoutes>`, this will be near the bottom of the file, add this line:
+3. In this same file just before the closing `</FlatRoutes>`, this will be near the bottom of the file, add this line:
 
    ```ts
    <Route path="/devtools" element={<DevToolsPage />} />

plugins/kubernetes/README.md

@@ -14,7 +14,7 @@ See our announcement blog post [New Backstage feature: Kubernetes for Service Ow
 
 ## Setup & Configuration
 
-This plugin must be explicitly added to a Backstage app, along with its peer backend plugin.
+This plugin must be installed in a Backstage app, along with its peer backend plugin.
 
 ```bash
 # From your Backstage root directory

plugins/org/README.md

@@ -43,7 +43,7 @@ For the full list of available extensions and their configuration options, see t
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 ### MyGroupsSidebarItem
 

plugins/scaffolder/README.md

@@ -24,18 +24,20 @@ Once installed, the plugin is automatically available in your app through the de
 
 ### Troubleshooting
 
-If you encounter the [issue of closing EventStream](https://github.com/backstage/backstage/issues/5535)
+If you encounter [issues with early closure of the `EventStream`](https://github.com/backstage/backstage/issues/5535)
 which auto-updates logs during task execution, you can enable long polling. To do so,
 update your `packages/app/src/apis.ts` file to register a `ScaffolderClient` with the
 `useLongPollingLogs` set to `true`. By default, it is `false`.
 
 ```typescript
 import {
+  AnyApiFactory,
   createApiFactory,
   discoveryApiRef,
   fetchApiRef,
   identityApiRef,
 } from '@backstage/core-plugin-api';
+import { scmIntegrationsApiRef } from '@backstage/integration-react';
 import {
   scaffolderApiRef,
   ScaffolderClient,
@@ -60,6 +62,7 @@ export const apis: AnyApiFactory[] = [
       }),
   }),
   // ... other factories
+];
 ```
 
 This replaces the default implementation of the `scaffolderApiRef`.
@@ -71,11 +74,11 @@ to launch the plugin locally using the `createDevApp` of the `./dev/index.tsx` f
 
 To play with it, open a terminal and run the command: `yarn start` within the `./plugins/scaffolder` folder
 
-**NOTE:** Don't forget to open a second terminal and to launch the backend or [backend-next](../../docs/backend-system/index.md) there, using `yarn start` and to specify the locations of the templates to play with !
+**NOTE:** Don't forget to open a second terminal and to launch the backend there, using `yarn start backend` and to specify the locations of the templates to play with!
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 ### Add the plugin to your `packages/app`
 

plugins/user-settings/README.md

@@ -22,7 +22,7 @@ Once installed, the plugin is automatically available in your app through the de
 
 ## Old Frontend System
 
-If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app.
+If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.
 
 ### Components Usage