Resolve "Review, adapt, and extend integration guide"

This MR adds a tested integration guide to the docs.

Can this MR be accepted?

• Documentation extended or updated
  • Added integration guide
  • Extended existing guides here and there
  • Enhanced crosslinks between docs
• No relevant code changes (except tested includes)

• Ready for merging
  • Pipeline passes without warnings
  • History cleaned-up or squash option set
  • Changelog entry added
  • Version number bumped (to 0.13.0a7)
  • Reviewed & approved by @herdeanu
  • Reviewed & approved by @jeremiastraub

Related issues

Closes #129 (closed)