--paired-paths on command line doesn't report pairing configured in jupytext.toml

[Aetf]

Basically as shown in the following:

❯ ls --tree
./
├── __notebooks__/
│  └── demo.ipynb
└── jupytext.toml
❯ cat jupytext.toml
formats = [
    "__notebooks__///ipynb",
    ".///py:percent"
]
❯ jupytext --paired-paths __notebooks__/demo.ipynb
❯ jupytext --sync __notebooks__/demo.ipynb
[jupytext] Reading __notebooks__/demo.ipynb in format ipynb
[jupytext] Updating ./demo.py
❯ jupytext --paired-paths __notebooks__/demo.ipynb
❯

I want a way to automatically generate paired py/md when opening a new notebook, similar to jupytext.vim.
But instead of generating a new text file as you mentioned in
#146 (comment), I hope the details could be controlled in
jupytext.toml. But for that, I need a way to tell where the paired text file is located.

[indigoviolet]

I'd like to report this issue as well:

# clearly these are paired
❯ jupytext --sync explore_osm_data.ipynb               
[jupytext] Reading explore_osm_data.ipynb in format ipynb
[jupytext] Loading explore_osm_data.py
[jupytext] Updating the timestamp of explore_osm_data.py

# and yet jupytext wont say so
❯ jupytext -p explore_osm_data.ipynb    

❯ cat ~/.config/jupytext.toml
formats = ["ipynb", "py:percent"]
notebook_metadata_filter = "all,-kernelspec,-jupytext.cell_metadata_filter,-jupytext.notebook_metadata_filter"
cell_metadata_filter = "-all"