Get the principles page under Zalando ownership

The open source guild links to a principals page, which haven't been updated for ages:
https://zalando-open-source-principles.readthedocs.io/en/latest/

The source of this page is on a former employees github page:
https://github.com/elezar/open-source-principles

While the principals is fine on their own, the document should be updated to reflect where we are now and become part of the SSOT (single source of truth)

Tasks

These are the concrete tasks to complete before the issue is marked as done:

• Figure out if we can take ownership of the readthedocs page
• Review the content
• Discuss the principals with the guild - do they still apply?
• Figure out where this should be stored going forward

Expected delivery

What is the concrete outcome of this work: principals page on opensource.zalando or on the guild page - or the removal of the principals page - depending on discussions

Stakeholders

Who do we need to align with to make this happen? - add the deparment to get in touch with

• OS Guild