Add (rudimentary) Synology DSM support

[vicchi]

Description

Added rudimentary Synology DSM support (see also #1275), via the DSM specific release metadata in /etc/VERSION as well as detecting packages via dpkg in addition to the current opkg support (if you're using the shell on a DSM box, you'll probably end up installing packages from Optware or Entware via the Easy Bootrap Installer comunity package. Well at least I did to get acme.sh running but that's another story).

Features

• Detects and reports the major.minor.patch DSM release, plus build number, plus update number
• Detects and reports packages installed via dpkg

Issues

Running shellcheck will fail with SC2154: [productversion|buildnumber|smallfixnumber] is referenced but not assigned if not run natively on DSM due to a dependency on sourcing the DSM /etc/VERSION file.

TODO

• Try and find a decent ASCII art version of the Synology logo

[hgy59]

@vicchi are you still working on this?

I did some enhancements that could be added to your PR:

• add unique dsm model information
• add Update version only when smallfixnumber > 0
• add DSM icon (this needs a small enhancement to support ascii_data with esc control sequences)

here is a sample output:

[hykilpikonna]

Thank you for your contribution!

This PR is merged into hyfetch since this repo (dylanaraps/neofetch) seems no longer maintained.

HyFetch is a fork of neofetch with LGBTQ pride flags, but the repo also maintains an updated version of the original neofetch, addressing many pull requests that are not merged in the original repo.

Read the "Running Updated Original Neofetch" section for more info!