The integration of Six has changed in 13.0. An IoT Box is no longer
required and the configuration has changed.
One of the steps for the configuration of the Ingenico terminal was
unnecessary.
- Removed the doc version and absolute path from all user doc redirections.
- Made developer doc redirections use 13.0 instead of online, master or earlier version string.
- Fixed outdated links.
- Enforced the use of :doc:, :ref: and :download: directives for redirections.
- Replaced google drive/docs links by doc redirections.
- Removed the numbering from headings because it was either inconsistent, breaking the implicit hyperlink target or useless.
- Fixed incorrect heading formattings.
- Replaced hand-written flows by the :menuselection: directive
