More prominent security warnings in install documentation

[pcrockett]

The usage documentation on Docker Hub shows a lot of examples for how to get Huginn running in Docker. Toward the end of the documentation there's a... soft... suggestion that you could check out .env.example if you wanted to, to see what other parameters you can configure.

I set up my Huginn instance a couple years ago. I was looking for email settings, so I quickly skimmed through that file and figured out how to customize those email-related environment variables. I totally missed that for security reasons, I need to also adjust the APP_SECRET_TOKEN and INVITATION_CODE environment variables.

Since those seem to be pretty important environment variables, should they be mentioned a bit more loudly in the documentation?

[github-actions]

This issue is stale because it has been open for 180 days with no activity.