Update HISTORY.rst

Author: mwouts

HISTORY.rst

@@ -19,6 +19,8 @@ Release History
 - R Markdown hidden inputs, outputs, or cells are now mapped to the corresponding Jupyter Book tags by default (#337)
 - The Jupyter Notebook extension for Jupytext is compatible with Jupyter Notebook 6.0 (#346)
 - ``jupytext notebook.py --to ipynb`` updates the timestamp of ``notebook.py`` so that the paired notebook still works in Jupyter (#335, #254)
+- ``jupytext --check pytest notebook.ipynb`` can be used to run test functions in a notebook (#286)
+- ``jupytext --check`` and ``jupytext --pipe`` can run commands that only operate on files: when ``{}`` is found in the text of the command, ``jupytext`` saves the text representation of the notebook in a temp file, and replaces ``{}`` with the name of that file before executing the command. (#286)
 - Added support for Rust/Evxcr, by Jonas Bushart (#351)
 - Added support for PowerShell (#349)