docs: added linux systemctl command (#64)

Author: clsource

docs/modules/developer/pages/dev_environment.adoc

@@ -58,16 +58,23 @@ $ sudo vim /etc/nix/nix.conf
 
 [source, text]
 ----
-trusted-users = root camilowser
+trusted-users = root <your-user>
 ----
 
 - 3. Reboot nix service
 
+.macOS
 [source, bash]
 ----
 sudo launchctl kickstart -k system/org.nixos.nix-daemon
 ----
 
+.Linux
+[source, bash]
+----
+sudo systemctl restart nix-daemon.service
+----
+
 == Direnv
 
 Install https://direnv.net/docs/installation.html#from-system-packages[Direnv] to automatically load _Devenv_ on entering the directory and load other system settings.