Add Buildstash

[r0bbie]

Pull Request Template

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

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

[github-actions]

New resource link: https://buildstash.com