Include Standard `.gitignore` and `README.md` in `startproject` Template

### Code of Conduct

- [x] I agree to follow Django's Code of Conduct

### Feature Description

Enhance the `startproject` command to include a standard, Django-specific `.gitignore` file and a basic `README.md` file in the initial project template, making project setup more complete and secure out of the box.

### Problem

Django's `startproject` command generates a minimal project structure, but it lacks several critical files that are considered standard in modern web development and version control practices. This omission creates several problems for developers:

1. Security Risks and Unnecessary Commits: The absence of a `.gitignore` file means that sensitive and non-essential files are often accidentally committed to the Git repository. These include:
- **Environment-specific configurations**: For example `.env` files (if used), or a `database.sqlite3` file.
- **Virtual environment files**: The `.venv/` or `env/` directory, which should never be part of a repository.
- **Compiled Python files**: `__pycache__` directories and `.pyc` files.
- **User-uploaded media**: The `media/` directory.

Without a default `.gitignore`, new developers are highly likely to commit these files, leading to security vulnerabilities (e.g., exposing API keys or secret keys) and polluting the repository with non-reproducible local files.

2. **Increased Friction for New Developers**: Django's "batteries-included" philosophy aims to provide a great out-of-the-box experience. However, the current `startproject` command forces developers to immediately stop, create a `.gitignore` file from scratch, and remember which files to exclude. This is a repetitive and unnecessary step, especially for those new to Django or web development. It makes the initial setup feel less streamlined and professional compared to other modern frameworks.

3. **Lack of Project Documentation**: A `README.md` file is a standard practice for documenting a project's purpose, setup instructions, and key information. By not including a basic `README.md`, Django misses an opportunity to guide developers on how to get started, run the server, and interact with the project immediately after it is created. It also provides a placeholder for the project's description, encouraging good documentation habits from the very beginning.

4. **Inconsistent Project Structure**: Developers often have to rely on third-party guides or external tools to generate a `.gitignore`, leading to inconsistencies across different Django projects. Integrating a core `.gitignore` and `README.md` ensures all projects have a consistent starting point.

### Request or proposal

request

### Additional Details

The proposed feature aligns with the modern standard for project scaffolding seen in other popular frameworks like Next.js, create-react-app, and even community-maintained templates for frameworks like Flask. The inclusion of these files would make the startproject command more robust and better suited for real-world projects that are immediately put under version control.

**Example `README.md` content**:

A minimal, yet helpful, `README.md` could contain:

```Markdown
# My Django Project

A brief description of your project.

## Getting Started

### Prerequisites

- Python 3.x
- pip (package installer)

### Installation

1. **Clone the repository:**
```bash
git clone [https://github.com/your-username/your-project.git](https://github.com/your-username/your-project.git)
cd your-project
```
2. **Create and activate a virtual environment:**
```bash
python -m venv .venv
source .venv/bin/activate # On Windows, use `.venv\Scripts\activate`
```
3. **Install dependencies:**
```bash
pip install -r requirements.txt
```
4. **Run migrations:**
```bash
python manage.py migrate
```
5. **Start the development server:**
```bash
python manage.py runserver
```

## Development
This section is for additional development notes.
```

**Example `.gitignore` content**:

A comprehensive but non-opinionated `.gitignore` would include:

```gitignore
# Byte-compiled / optimized / DLL files
__pycache__/
*.py[cod]
*$py.class

# C extensions
*.so

# Distribution / packaging
.Python
build/
develop-eggs/
dist/
eggs/
*.egg-info/
.installed.cfg
*.manifest

# Environments
.env
.venv/
env/
venv/

# IDE files
.idea/
.vscode/

# Django-specific files
*.log
*.sqlite3
db.sqlite3
media/

# Uploaded media
/uploads/
/static_collected/

# Others
.DS_Store
.mypy_cache
.ruff_cache
.coverage
htmlcov
```

The inclusion of these files by default would significantly improve Django's initial project setup, especially for new users.

### Implementation Suggestions

_No response_