README: document enabling/disabling services

Support for enabling/disabling services has been added in
54f7665 but was so far not
documented, which made it hard to find.

This is a very useful feature for people who prefer to avoid relying
on the proprietary application to enable services, so add it to the
main README file.

Signed-off-by: Raphaël Mélotte <[email protected]>

Author: rmelotte

README.md

@@ -570,6 +570,22 @@ neolink ptz --config=config.toml CameraName zoom 2.5
 
 With 1.0 being normal and 2.5 being 2.5x zoom
 
+### Enabling services (http, https, rtmp, rtsp and onvif)
+
+Services can be enabled/disabled using the `services` command.
+
+For example, to enable the http port:
+```bash
+neolink services --config=/etc/neolink.toml CameraName http on
+```
+
+To disable it:
+```bash
+neolink services --config=/etc/neolink.toml CameraName http off
+```
+
+Note that this might not work on older camera models.
+
 ## License
 
 Neolink is free software, released under the GNU Affero General Public License