Example: Build your custom GitHub Action
To build your action, run npm run bundle. This will compile the TypeScript code in the src/ directory and output the JavaScript code in the dist/ directory. The exact command for bundle is defined in the package.json file.
Note: About custom actions
Actions are individual tasks that you can combine to create jobs and customize your workflow. Y Types of action You can build Docker container, JavaScript, and composite actions.
Reference:
https://victoronsoftware.com/posts/typescript-github-action/
https://docs.github.com/en/actions/concepts/workflows-and-actions/custom-actions