Inspired by Typora, Bear, and other WYSIWYG software
When the header line is not active, Hashes (#) are replaced with H[1-6]
When the header line is active, Hashes are shown and H[1-6] are hidden
Note: This differs from other existing CSS hacks in that the H[1-6] are NOT displayed in the gutter. So you can still use this when you turn off the display of line numbers.
2020-12-10: Now compatible with the Minimal Theme