Apply suggestions from code review

Co-authored-by: Philipp Schuster <[email protected]>

book/src/tutorial/app.md

@@ -16,10 +16,16 @@ cd my-uefi-app
 Add a few dependencies:
 
 ```sh
-cargo add log uefi
+cargo add log
+cargo add uefi --features logger panic_handler
 ```
 
-You'll need to add some feature flags and configuration to Cargo.toml as well:
+Also you have to add 
+```toml
+[profile.dev]
+panic="abort"
+```
+to your `Cargo.toml`. The resulting `Cargo.toml` should look like that:
 ```toml
 [dependencies]
 log = "0.4.21"