docs: add the development guide on how to run test

Development.md

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+# Development Guide
+
+This guide will help you set up the `generator` locally, run tests, and use Docker for isolated testing.
+
+## Getting Started
+
+1. Clone the repository:
+
+```bash
+git clone https://github.com/asyncapi/generator.git
+cd generator
+```
+
+2. Install dependencies:
+
+```bash
+npm install
+```
+
+## Running Tests
+
+### Local Testing
+
+To run all tests locally:
+
+- Unit tests: `npm run generator:test:unit`
+- Integration tests: `npm run generator:test:integration`
+- CLI tests: `npm run generator:test:cli`
+
+### Adding Tests
+
+1. Create new test files in the appropriate directory under `test/`:
+
+2. Follow the existing test patterns.
+
+3. Run your new tests using the commands mentioned above.
+
+## Docker Isolated Testing
+
+To run tests in an isolated Docker environment:
+
+1. Ensure Docker is installed and running on your machine.
+
+2. Run the following command from the project root:
+
+```bash
+docker run --rm -v ${PWD}:/app -w /app node:18 sh -c "
+cp -r /app /tmp/app &&
+cd /tmp/app &&
+npm install &&
+npm test
+"
+```
+
+This command does the following:
+- Mounts the current directory to `/app` in the container
+- Copies the project to a temporary directory
+- Installs dependencies
+- Runs all tests
+
+Note: This approach ensures a clean environment for each test run by removing any existing `node_modules`.
+
+## Additional Commands
+
+- Lint the code: `npm run lint`
+- Generate documentation: `npm run docs`
+- Build Docker image: `npm run docker:build`
+
+## Troubleshooting
+
+If you encounter any issues during development or testing, please check the following:
+
+1. Ensure you're using the correct Node.js version (18.12.0 or higher) and npm version (8.19.0 or higher).
+2. Clear the `node_modules` directory and reinstall dependencies if you encounter unexpected behavior.
+3. For Docker-related issues, make sure Docker is running and you have sufficient permissions.
+
+If problems persist, please open an issue on the GitHub repository.