Create a folder named mm in the working directory (getwd()), and drop some markdown or rmarkdown files into mm/. Run:
mindr::md2mm()
then you will get an mm.mm file. Open or import it with any mind-map (brainstorm) software, and you will get a mind map.
Plenty of cross-platform and online mindmap software suits are available (see the list), among which FreeMind and XMind are highly recommended.
Drop some mindmap files (.mm) into mm/. Run:
mindr::mm2md()
then you will get a mm.md markdown file.
Drop some markdown or rmarkdown files into mm/. Run:
mindr::outline()
then you will get an outline.md file with headers in it as an outline.
Have fun!
Still being developed. Feel free to give your feedback to me!