[update] Write introduction into API lifecycle

Context

While discussing the compatibility chapter refactoring the idea came up to include a brief introduction to the API lifecycle as part of the Core principles in the API Guidelines.

To do

• Clarify the wording "shutdown" and "removal".
• Suggest new section "API lifecycle" as a pull request based on the drafts attached to this issue in the comments.
• Have pull request reviewed by a Technical Writer and an API coach.

Deliverables

New section "API lifecycle" available in the API Guidelines.

Further information

Topics, that should be explained with possible references to compatibility chapters (for REST and Events) for further detailing information about how to do it:

1. Introduction of new APIs
2. Compatible extensions of APIs
3. Incompatible extensions of APIs
4. End of life of APIs

Original: slinstaedt
opened [on Mar 3, 2022]

Internal issue: https://github.com/otto-ec/techwriting_hub/issues/16

Start with the API Guidelines' Core principles and the linked REST and Events compatibility chapters. Review the drafts referenced in the issue comments, if available, and clarify the terms “shutdown” and “removal.” Done means a reviewed “API lifecycle” section covering API introduction, compatible and incompatible extensions, and end of life.