The biggest change in `nbformat` 5.5.0 is the deprecation of arguments
to `validate()` that try to fix notebooks errors during validation.
`validate()` is a function that is core to the security model of
Jupyter, and is assumed in a number of places to not mutate it's
argument, or try to fix notebooks passed to it.
Auto fixing of notebook in validate can also hide subtle bugs, and will
therefore be updated in a near future to not take any of the argument
related to auto-fixing, and fail instead of silently modifying its
parameters on invalid notebooks.
`nbformat` now contain a `normalize` function that will return a
normalized copy of a notebook that is suitable for validation. While
offered as a convenience we discourage its use and suggest library make
sure to generate valid notebooks.
Other changes
- `nbformat` is now built with flit, and uses `pyproject.toml`
- Documentation and Deprecations have been updated with version number
and stack levels.