Fix `--directory` path in examples (#12165)

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## Summary

<!-- What's the purpose of the change? What does it do, and why? -->
The examples assume that the packages are in the project root directory.
However, they are nested inside `src`, and the commands in the examples
do not work as intended.

I could not find any related issues.

## Test Plan

<!-- How was it tested? -->

I tested it by executing the commands on my terminal - Linux and Windows
(PowerShell).

---------

Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>

docs/concepts/projects/init.md

@@ -65,6 +65,7 @@ if __name__ == "__main__":
 Python files can be executed with `uv run`:
 
 ```console
+$ cd example-app
 $ uv run main.py
 Hello from example-project!
 ```
@@ -90,7 +91,7 @@ example-pkg
 ├── README.md
 ├── pyproject.toml
 └── src
-    └── example_packaged_app
+    └── example_pkg
         └── __init__.py
 ```
 
@@ -107,7 +108,7 @@ requires-python = ">=3.11"
 dependencies = []
 
 [project.scripts]
-example-pkg = "example_packaged_app:main"
+example-pkg = "example_pkg:main"
 
 [build-system]
 requires = ["hatchling"]
@@ -130,7 +131,7 @@ requires-python = ">=3.11"
 dependencies = []
 
 [project.scripts]
-example-pkg = "example_packaged_app:main"
+example-pkg = "example_pkg:main"
 
 [build-system]
 requires = ["hatchling"]
@@ -140,7 +141,8 @@ build-backend = "hatchling.build"
 The command can be executed with `uv run`:
 
 ```console
-$ uv run --directory example-pkg example-pkg
+$ cd example-pkg
+$ uv run example-pkg
 Hello from example-pkg!
 ```
 
@@ -213,7 +215,8 @@ def hello() -> str:
 And you can import and execute it using `uv run`:
 
 ```console
-$ uv run --directory example-lib python -c "import example_lib; print(example_lib.hello())"
+$ cd example-lib
+$ uv run python -c "import example_lib; print(example_lib.hello())"
 Hello from example-lib!
 ```
 
@@ -291,7 +294,8 @@ def main() -> None:
 The command can be executed with `uv run`:
 
 ```console
-$ uv run --directory example-ext example-ext
+$ cd example-ext
+$ uv run example-ext
 Hello from example-ext!
 ```