Update installation_script

docs/installation_script

@@ -1,7 +1,15 @@
-    # sudo apt update && apt upgrade
-    # sudo apt install git ca-certificates nginx rabbitmq-server mongodb lxd build-essential libssl-dev libffi-dev python3-dev virtualenv
-    # sudo newgrp lxd
-    # sudo lxd init
+Optional, if you want to wrap Pirus into a lxc container:
+    $ echo 'lxc.mount.auto = cgroup
+    lxc.aa_profile = lxc-container-default-with-nesting' >> ~/.config/lxc/default.conf
+    $ lxc-create -n regovar_pirus -t download -- -d ubuntu -r xenial -a amd64
+    $ lxc-start -n regovar_pirus
+    $ lxc-attach -n regovar_pirus
+
+Installation script for Pirus on a fresh Ubuntu Xenial:
+    # apt update && apt upgrade
+    # apt install git ca-certificates nginx rabbitmq-server mongodb lxd build-essential libssl-dev libffi-dev python3-dev virtualenv
+    # newgrp lxd
+    # lxd init
     # useradd pirus --create-home
     # sudo usermod -a -G lxd pirus
     # mkdir -p /var/regovar/pirus/{cache,downloads,files,databases,pipelines,runs}