Fix: Correct directory name in setup documentation

[MuzakkirHossainMinhaz]

This pull request addresses a minor issue in the documentation where the directory name mentioned in the setup instructions was incorrect.

Changes Made:
Replaced new-sample-app with the correct directory name my-project in the setup instructions.

Reason for Change:
The command intent new my-project creates a project directory named my-project. To ensure clarity and avoid confusion for users, the directory name in the documentation should match the output of the command.