mention Onecall 3.0 option in the documentation

[sanderkob]

Which node are you reporting an issue on?

node-red-node-openweathermap version 1.0.1

What are the steps to reproduce?

What happens?

What do you expect to happen?

Please tell us about your environment:

• Node-RED version: 3.1.9
• node.js version: 20.13.1
• npm version: 10.5.2
• Platform/OS: Windows
• Browser: Chrome

In anticipation of the coming switch to Onecall 3.0 I registered for a subscription.
However, it was not clear to me how to invoke a call to 3.0 in the openweathermap node.
After some digging through the code I found that the option onecall 3.0 can be found in the dropdown menu of the node properties page as "combined current weather/forecast for".
To help users, I prepared a PR for the help file.

[sanderkob]

#PR 317

[dceejay]

Are you able to click/sign the PR, so we can accept/merge it ?
Thanks,