Clarify the datasets list on the "Create an issue" doc page

[jypeter]

In the The datasets list is mandatory section of the Create an issue page, it would be nice to give one (or more) example datasets, e.g. CMIP6.ScenarioMIP.IPSL.IPSL-CM6A-LR.ssp245.r2i1p1f1.day.uas.gr#20190119 , the way you do it on the Track a version page

And it would be very useful to specify if you can use wildcards (and give an example) or not

I'm wondering for example how the Wrong parent variable label in ssp245 (r2i1p1f1) issue with 754 affected datasets was created. I had a quick look at the CLI documentation, but I did not find any mention of wildcards

I will need to know this if I want to create an errata for the full midHolocene IPSL r1p1i1f2 experiment. I guess that the special case of creating an errata for a full experiment could be useful for other people