Apply suggestions from code review

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

Co-authored-by: Fredrik Adelöw <freben@gmail.com>

plugins/api-docs/README.md

@@ -33,7 +33,7 @@ To link that a component provides or consumes an API, see the [`providesApis`](h
 yarn add @backstage/plugin-api-docs
 ```
 
-2. Add the `ApiExplorerPage` extensions to the app:
+2. Add the `ApiExplorerPage` extension to the app:
 
 ```tsx
 // packages/app/src/App.tsx

plugins/catalog-import/README.md

@@ -23,7 +23,7 @@ Some features are not yet available for all supported Git providers.
 yarn add @backstage/plugin-catalog-import
 ```
 
-2. Add the `CatalogImportPage` extensions to the app:
+2. Add the `CatalogImportPage` extension to the app:
 
 ```tsx
 // packages/app/src/App.tsx

plugins/rollbar/README.md

@@ -30,7 +30,7 @@ const serviceEntityPage = (
 );
 ```
 
-4. Setup the `app.config.yaml` and account token environment variable
+4. Setup the `app-config.yaml` and account token environment variable
 
 ```yaml
 # app.config.yaml