Add some more "netiquette" rules for on slack

[eldering]

No description provided.

[vmcj]

I think mentioning the relevant files is also helpful:

When you have problems installing please provide us which guide you followed and what is the output of the different steps. Provide the relevant parts of your history and the output of earlier steps. How did you run configure, what was the output of the make steps etc.

When the domserver doesn't load, please provide us with the webserver log and the var log in <domjudge_install_dir>/webapp/var/log/*.log

[eldering]

I think mentioning the relevant files is also helpful:

When you have problems installing please provide us which guide you followed and what is the output of the different steps. Provide the relevant parts of your history and the output of earlier steps. How did you run configure, what was the output of the make steps etc.

When the domserver doesn't load, please provide us with the webserver log and the var log in <domjudge_install_dir>/webapp/var/log/*.log

Let's add that in the pinned message in the #general channel. I guess there there's a bigger chance people read it when submitting questions.