Update GitHub Actions for React Project Validation and Docker Hub Image Push

[KaueReinbold]

Description:
Enhance the GitHub Actions workflow to automate the validation of the React project within the Reminders application when a pull request is created or updated. Additionally, set up a new GitHub Action to push the Docker image to Docker Hub upon the completion of a pull request for the React project.

Suggested Changes:

Update Existing Action (.github/workflows/react-pull-request.yml):

• Configure the workflow to validate the React project specifically in the folder src/app/reactjs/reminders-app.
• Ensure that the validation process includes linting, testing, and any other relevant checks.
• Set up status checks to prevent merging if the validation fails.

Create New Action (.github/workflows/docker-hub-react.yml):

• Develop a new GitHub Action workflow to run after the pull request for the React project is completed.
• Implement the workflow to build and push the Docker image for the React project to Docker Hub.
• Include necessary authentication and credentials for Docker Hub.

Note:
Ensure that the workflows are well-documented, and any sensitive information, such as credentials, is securely handled in the GitHub Actions settings.