clarify the debug scenario

[jeffmcaffer]

The original text was ambiguous as the user just added a Debug node and there is a sidebar for that node called "debug". There also, it turns out, is a Debug sidebar (vs the Info sidebar). I was injecting and injecting and nothing was happening...

The doc might be a bit better if it included the actual icon in the text but I did not see that in the images folder.

[jsf-clabot]

All committers have signed the CLA.

[knolleary]

Thanks for raising this. The icon is available via CSS - will look at it tomorrow.

In addition, we should link each term to the relevant bit of the editor guide the first time it is referenced. This will help new users discover the editor guide. https://nodered.org/docs/user-guide/editor/