Fix the handling of bibliography sections in R Markdown notebooks

[mwouts]

Will close #1161

[github-actions[bot]]

Thank you for making this pull request.

Did you know? You can try it on Binder: or .

Also, the version of Jupytext developed in this PR can be installed with pip:

pip install git+https://github.com/mwouts/jupytext.git@fix_bibliography_in_rmarkdown

(this requires nodejs, see more at Developing Jupytext)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (4a133b5) 96.81% compared to head (aa55b9d) 97.73%. Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1180 +/- ## ========================================== + Coverage 96.81% 97.73% +0.92% ========================================== Files 29 29 Lines 4452 4456 +4 ========================================== + Hits 4310 4355 +45 + Misses 142 101 -41 ``` | [Flag](https://app.codecov.io/gh/mwouts/jupytext/pull/1180/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts) | Coverage Δ | | |---|---|---| | [external](https://app.codecov.io/gh/mwouts/jupytext/pull/1180/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts) | `75.17% <40.00%> (+0.06%)` | :arrow_up: | | [functional](https://app.codecov.io/gh/mwouts/jupytext/pull/1180/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts) | `88.56% <100.00%> (+0.01%)` | :arrow_up: | | [integration](https://app.codecov.io/gh/mwouts/jupytext/pull/1180/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts) | `77.31% <40.00%> (-0.05%)` | :arrow_down: | | [unit](https://app.codecov.io/gh/mwouts/jupytext/pull/1180/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts) | `66.56% <20.00%> (-0.07%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Marc+Wouts#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.