Convert all markdown files to ipynb notebook using jupytext

md_to_ipynb.sh

jupytext --set-formats ipynb,md --sync ./first_test.ipynb ## sync a notebook with md
jupytext --to ipynb first_test.md                         ## make notebook from md

find . -type f  -name "*.md" | xargs jupytext --to ipynb  ## find all md files in the current dir and make their notebooks