Please add output for system's display manager as well

[sdbbs]

I'm submitting a ... (check one with "x")

[ ] bug report
[ ] new distro request
[x] feature request

Currently, latest ./screenfetch-dev outputs this for me:

$ ./screenfetch-dev -n
 user@PC
 OS: Ubuntu 20.04 LTS (Focal Fossa)
 Kernel: x86_64 Linux 5.4.0-189-generic
 Uptime: 7d 18h 23m
 Packages: 2683
 Shell: bash 5.0.17
 Resolution: 1366x768
 DE: MATE 1.24.0
 WM: Metacity (Marco)
 WM Theme: Ambiant-MATE
 GTK Theme: Ambiant-MATE [GTK2/3]
 Icon Theme: Ambiant-MATE
 Font: Ubuntu 11
 Disk: 208G / 250G (84%)
 CPU: Intel Core i5-2520M @ 4x 3.2GHz [64.0°C]
 GPU: Mesa DRI Intel(R) HD Graphics 3000 (SNB GT2)
 RAM: 5122MiB / 7827MiB

So, it outputs Desktop Environment and Windows Manager, but it does not output display manager.

Would it be possible to add display manager output to screenFetch as well? From https://unix.stackexchange.com/questions/20370/is-there-a-simple-linux-command-that-will-tell-me-what-my-display-manager-is I found:

$ systemctl --property=Id,Description show display-manager.service
Id=lightdm.service
Description=Light Display Manager

... which I think is enough of an information to be included in screenfetch.