init: Use main as default function in packaged app

Create a function main as the default for a packaged app.
Configure the default executable as:

example-packaged-app = "example_packaged_app:main"

Which is often what you want - the executable has the same name as the
app.

crates/uv/src/commands/project/init.rs

@@ -460,7 +460,7 @@ impl InitProjectKind {
         if package {
             // Since it'll be packaged, we can add a `[project.scripts]` entry
             pyproject.push('\n');
-            pyproject.push_str(&pyproject_project_scripts(name, "hello", "hello"));
+            pyproject.push_str(&pyproject_project_scripts(name, name.as_str(), "main"));
 
             // Add a build system
             pyproject.push('\n');
@@ -479,7 +479,7 @@ impl InitProjectKind {
                 fs_err::write(
                     init_py,
                     indoc::formatdoc! {r#"
-                    def hello() -> None:
+                    def main() -> None:
                         print("Hello from {name}!")
                     "#},
                 )?;

docs/concepts/projects.md

@@ -231,7 +231,7 @@ example-packaged-app
 But the module defines a CLI function:
 
 ```python title="__init__.py"
-def hello() -> None:
+def main() -> None:
     print("Hello from example-packaged-app!")
 ```
 
@@ -247,7 +247,7 @@ requires-python = ">=3.11"
 dependencies = []
 
 [project.scripts]
-hello = "example_packaged_app:hello"
+example-packaged-app = "example_packaged_app:hello"
 
 [build-system]
 requires = ["hatchling"]
@@ -257,7 +257,7 @@ build-backend = "hatchling.build"
 Which can be executed with `uv run`:
 
 ```console
-$ uv run hello
+$ uv run example-packaged-app
 Hello from example-packaged-app!
 ```