Add configuration "tab_stop_width" and "is_expand_tab". Expand tab to
tab_stop_width spaces if is_expand_tab is true.
Signed-off-by: Le Tan <tamlokveer@gmail.com>
1. Add menu item "Converter" to choose markdown converter;
2. Add menu item "About" and "About Qt";
3. Change all QMessageBox's parent to "this";
Signed-off-by: Le Tan <tamlokveer@gmail.com>