Clarify issue/PR choreography

From a discussion with @picnixz:

I think the problem with the devguide is the first sentence is "Create an issue that describes the change" and you'll see the mention to DPO only during creation. We can improve that
I would expect people to read the issue template correctly and understand that something is not trivial
and more importantly: WAIT for triagers to decide whether it's ok or not as an issue
There are obvious cases where the issue doesn't a triager for validation, like a clear bug (and even this is subject to interpretation sometimes) but the process issue+PR is the worst for triagers, especially when the PR is automated.

This might be a duplicate of other feedback here in issues, but I wanted to capture it before going back to $WORK.

Inizia individuando le istruzioni iniziali del devguide e il template dell’issue, quindi verifica dove vengono introdotte le indicazioni su DPO e sui triager. Chiarisci che i contributor devono attendere la convalida di un triager prima di aprire una PR, tenendo presente anche la discussione sui bug evidenti. Il lavoro è completato quando il workflow issue-to-PR e le eccezioni sono espliciti per i contributor.