Docs website with mkdocs (#100)

* Fix build workflow

* Docs website with mkdocs (#99)

* Fix docs workflow

* Move mkdocs Docker file

* Ignore docs in build workflow

* Update workflows

* Update links

* Move upgrade notes to documentation

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

docs/install/linux-service.md

@@ -0,0 +1,43 @@
+# Run as service on Debian based distro
+
+## Using systemd
+
+!!! warning
+    Make sure to follow the instructions to [install from binary](binary.md) before.
+
+To create a new service, paste this content in `/etc/systemd/system/diun.service`:
+
+```
+[Unit]
+Description=Diun
+Documentation={{ config.site_url }}
+After=syslog.target
+After=network.target
+
+[Service]
+RestartSec=2s
+Type=simple
+User=diun
+Group=diun
+ExecStart=/usr/local/bin/diun --config /etc/diun/diun.yml --log-level info
+Restart=always
+Environment=DIUN_DB_PATH=/var/lib/diun/diun.db
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Change the user, group, and other required startup values following your needs.
+
+Enable and start Diun at boot:
+
+```shell
+$ sudo systemctl enable diun
+$ sudo systemctl start diun
+```
+
+To view logs:
+
+```shell
+$ journalctl -fu diun.service
+```