Add information on junctions to wire documentation

[unikitty37]

A while ago, I added junctions to some wires. Today, I needed to do it again, and couldn't remember what keys to hold down while dragging. The documentation doesn't mention junctions at all.

Once I found out that they were called junctions (searching for "node red split wire" doesn't produce useful results) I found something in the 3.0 release notes but it took over 10 minutes in all.

Could something be added to the documentation covering this feature? I can submit a PR for the text, but I'm not really in a position to generate helpful images at the moment unless I just lift the ones from the release notes.

[knolleary]

Hi @unikitty37 - you are quite right, they were missing in the last docs update. I'll make sure stuff gets added.