Revert "toc depth = 5"

This reverts commit de5fb0bf79e327512974637e72b80ca0eb6eec03.
Revert "fix toc"

This reverts commit ef660cfc0e604d50a98cb8a8d0cb3996962f020a.
Revert "use include instead of toc"

This reverts commit c7c5404f96127886e798279b3dd6d49c73115d93.