Please add your migration guide entries here. Until 3.0 is released, each PR
that makes backwards-incompatible changes should add a file here, with the
extension .md, a descriptive name and the following format:

---%<------%<------%<------%<------%<------%<------%<------%<---

The change that was made
------------------------

Who exactly is affected: does this affect users of the default config, of a
particular feature? Remember to contextualise.

If I'm affected, what's my migration path? How should I change my code if this
is an API change; if a feature was removed what are my alternatives?

---%<------%<------%<------%<------%<------%<------%<------%<---

PRs that make multiple independent changes should include one entry for each
changes or logical groups of changes. You can either add multiple files or put
multiple entries in the same file.

For examples, have a look a docs/3.0-migration-guide.md (which includes the
top-level header and an intro before the list of entries).

As part of release preparation, the entries in this directory will be appended
to docs/3.0-migration-guide.md and then re-ordered and reviewed one last time.
The file is then going to be moved to the version-independent docs repo.