Update alteropen

[StevePhuc]

Pull Request Template

Please ensure all items below are checked before creating a pull request:

• [x] My changes were made in the resources folder, not in the auto-generated README.md file or db folder
• [x] My submission is formatted according to the guidelines in the contributing guide
• [x] My submission is ordered alphabetically based on the resource name
• [x] My submission has a useful description
• [x] I have searched the repository for any relevant issues or pull requests

[JuanPabloDiaz]

https://alteropen.com seems like a great resource. Thank you @StevePhuc