Hey @Slion !
Thanks for your plugin, but I have a little error.
When I put Bold + Heading 1, I got this alert :
[E_NOTICE] Array to string conversion : src/addons/Slions/Toc/BbCode.php:166
#0 src/addons/Slions/Toc/BbCode.php(166): XF::handlePhpError(8, '[E_NOTICE] Arra...', 's...', 166...