A simple webpage that helps to create an *.items file for openHAB 2.5.10 and 3.0 (using API Token, see below)
cd /etc/openhab2/html
git clone https://github.com/Stefan300381/openHAB_ItemCreator
sudo chown -R openhab:openhab openHAB_ItemCreator/
The first field (API Token) should be ignored for openHAB 2 instances. For openHAB 3 you need to create an API token first (and insert it here) to authorize any client using the REST web services. To do so you, login to your local "create API Token" portal:
http://OPENHAB_HOST:OPENHAB_PORT/createApiToken