Platypus: Have Qiskit textbook running in Mathigon server

[lerongil]

• [x] Begin conversation with Mathigon
• [x] Qiskit to publish the content of the textbook to a public repository
• [x] Qiskit to setup GitHub actions for interacting with Mathigon build process.
• [x] Qiskit to provide the domains for hosting and e-mail functionality.
• [x] DNS configuration.
• [x] SSL setup

[lerongil]

Thanks Va!