Can't type [ or ] using a french keyboard on Windows

[jeberger]

On french keyboards, the [ and ] characters are obtained by pressing the right Alt key (commonly called AltGr) along with the ( and ) keys. For historical reasons Windows interprets AltGr as if it was Ctrl+Alt (in fact we can get [ by typing Ctrl+Alt+( even though nobody does it). As a consequence the Markdownx editor interprets any [ or ] character as if the Ctrl key was pressed and uses it to control indentation instead of inserting the character.