chore: rename examples folder (!94)

* Rename the `examples` folder to `_examples` to distinguish it from source code folders

https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/merge_requests/94

_examples/systemd/README.md

@@ -0,0 +1,7 @@
+# Systemd
+
+The `.service` file in this directory should be copied to the `/etc/systemd/system/` folder.
+- It expects the binary file to be installed at `/usr/sbin/fail2ban_exporter`.
+- It expects a user named `fail2ban_exporter` to exist. This user should not have a shell or any special privileges aside from read-access to the fail2ban socket file.
+
+The `ExecStart` line can be modified to add any custom CLI flags.

_examples/systemd/fail2ban_exporter.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Fail2Ban Exporter
+
+[Service]
+User=fail2ban_exporter
+ExecStart=/usr/sbin/fail2ban_exporter
+
+[Install]
+WantedBy=multi-user.target