webpage: update nix documentation

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

webpage/src/installation/nix.md

@@ -1,17 +1,19 @@
 # Install via Nix
 
-You can install QOwnNotes with the [Nix package manager](https://wiki.nixos.org/wiki/Nix_package_manager)
-on [NixOS](https://nixos.org/) and other platforms, the package name is
-[qownnotes](https://search.nixos.org/packages?channel=unstable&show=qownnotes).
+You can install QOwnNotes with the [Nix package manager](https://nixos.org/download/)
+on [NixOS](https://nixos.org/), other Linux distributions, macOS and Windows.
+The package name is [qownnotes](https://search.nixos.org/packages?channel=unstable&show=qownnotes).
+
+The package is built with Qt6 and provides shell integration for fish and bash.
 
 See [QOwnNotes on nix](https://search.nixos.org/packages?channel=unstable&show=qownnotes)
 for more information.
 
-Afterward you should be able to run QOwnNotes with the command `qownnotes`.
+Afterward you should be able to run QOwnNotes with the command `qownnotes` or `QOwnNotes`.
 
 ::: tip
 The QOwnNotes command-line snippet manager [qc](https://github.com/qownnotes/qc)
 can also be installed via the [Nix Store](https://search.nixos.org/packages?channel=unstable&show=qc).
 
-You can use `nix-shell -p qc --run qc` to try it out.
+You can use `nix-shell -p qc --run "qc exec"` to try it out.
 :::