Allow setting the contact and docs url with env variables.

[hareland]

Simply allows setting the contact and docs url with env variables.

[andrasbacsai]

Thank you for the PR!

Why do you need this? This is a step to white-labeling.

[hareland]

Thanks for your reply. This is mainly because i run this internally in a volunteer organization, and a lot of people who logs in gets confused if they are looking for help. I could keep a fork for this but figured other people might also encounter this issue.

[hareland]

@andrasbacsai It might be better to add a optional "help" button on the sidebar with a admin setting instead tho - what do you think would be a better approach?