[Request] Welcome message for new commiters from bot

Hello,

After some discussions at QtCS23, we believe it might be helpful that when a change is submitted to Gerrit by an account that's new, we could automate a welcome message
pointing out a few details of the process, and maybe point them to our https://wiki.qt.io/Online_Communities wiki page so the person knows where to find help.

A default message could be:

Welcome to the Qt Project {username},
we have detected this is your first collaboration, so many thanks!
In case you have questions, don't forget to visit any platform in https://wiki.qt.io/Online_Communities to get help from fellow contributors.

We could totally massage and open for discussion wrt the message content, but I believe it can help newcomers.

Bonus

The problem I have seen too, is that new committers forget to add reviewers, so I was thinking on having something else on the message (or maybe a new message from the bot?) reminding people to add reviewers for their change. This can of course can be trigger after X minutes when the patch was sent and no reviewers were added.

[Sorry if the component is not the proper one, I couldn't find a generic bot one]