jeltsch's blog

Directory hard links in Linux are forbidden. To emulate something similar, you can mount any file system path into any other directory. However, you need to be careful because you can get the same problems as with directory hard links, namely circular and thus infinite file paths...
sudo mount --bind /home/user/Documents/Desktop/ /home/user/Desktop/
Such a link disappears after a reboot. If you want to make it permanent, you can add the mount to /etc/fstab:
/home/user/Documents/Desktop/ /home/user/Desktop none bind

Adding a new python version to Ubuntu 20.04 (the 3rd after 2.7 and 3.8):
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.6 3

To change between python versions:
sudo update-alternatives --config python

Grub2 has been the default boot loader for Ubuntu for more then 10 years now. Its configuration file is nowadays /boot/grub/grub.cfg, but you MUST NOT edit /boot/grub/grub.cfg in order to modify the Grub boot menu.
Instead, you need to add your own entries to the file /etc/grub.d/40_custom. Some general preferences are also set in the the file /etc/default/grub and any file under /etc/default/grub.d/.