docs: use git switch -c instead of git checkout -b

Author: AlexanderLanin

docs/tutorials/first-pull-request.md

@@ -9,7 +9,7 @@ Complete [Getting Started](getting-started.md) first. You need a working devcont
 ## 1. Create a branch
 
 ```bash
-git checkout -b my-first-change
+git switch -c my-first-change
 ```
 
 Use a descriptive branch name for real contributions (e.g., `fix/typo-in-readme` or `feat/add-unit-test`).