Merge branch 'backstage:master' into suuus/docs-2

docs/getting-started/app-custom-theme.md

@@ -54,7 +54,7 @@ For example, adding the theme that we created in the previous section can be
 done like this:
 
 ```ts
-import { createApp } from '@backstage/core-app-api';
+import { createApp } from '@backstage/app-defaults';
 
 const app = createApp({
   apis: ...,

docs/getting-started/create-an-app.md

@@ -36,7 +36,7 @@ This will create a new Backstage App inside the current folder. The name of the
 app-folder is the name that was provided when prompted.
 
 <p align='center'>
-  <img src='../assets/getting-started/create-app_output.png' width='600' alt='create app'>
+  <img src='../assets/getting-started/create-app_output.png' width='600' alt='create app' />
 </p>
 
 Inside that directory, it will generate all the files and folder structure

docs/getting-started/project-structure.md

@@ -166,13 +166,9 @@ are separated out into their own folder, see further down.
   plugin and [techdocs-cli](https://github.com/backstage/techdocs-cli).
 
 - [`test-utils/`](https://github.com/backstage/backstage/tree/master/packages/test-utils) -
-  This package contains more general purpose testing facilities for testing a
+  This package contains general purpose testing facilities for testing a
   Backstage App or its plugins.
 
-- [`test-utils-core/`](https://github.com/backstage/backstage/tree/master/packages/test-utils-core) -
-  This package contains specific testing facilities used when testing Backstage
-  core internals.
-
 - [`theme/`](https://github.com/backstage/backstage/tree/master/packages/theme) -
   Holds the Backstage Theme.