Add CLI output and README how to start app after create-app CLI

Signed-off-by: Otto Sichert <git@ottosichert.de>

.changeset/seven-ligers-watch.md

@@ -0,0 +1,5 @@
+---
+'@backstage/create-app': patch
+---
+
+Add CLI output and README how to start app after create-app CLI

packages/create-app/README.md

@@ -15,6 +15,7 @@ $ npx @backstage/create-app
 With a local clone of this repo, from the main `create-app/` folder, run:
 
 ```sh
+$ yarn
 $ yarn backstage-create-app
 ```
 

packages/create-app/src/createApp.ts

@@ -148,6 +148,7 @@ export default async (cmd: Command): Promise<void> => {
     );
     Task.log();
     Task.section('All set! Now you might want to');
+    Task.log(`  Run the app: ${chalk.cyan(`cd ${answers.name} && yarn dev`)}`);
     Task.log(
       '  Set up the software catalog: https://backstage.io/docs/features/software-catalog/configuration',
     );

packages/create-app/templates/default-app/README.md

@@ -1,3 +1,10 @@
 # [Backstage](https://backstage.io)
 
 This is your newly scaffolded Backstage App, Good Luck!
+
+To start the app, run:
+
+```sh
+$ yarn
+$ yarn dev
+```