Dead link in the README

[pieterocp]

The link to more comprehensive docs about the how session_duration works doesn't load:

More information about how session_duration works in intercom documentation

The link just sends me around the houses. I have never seen what this was meant to talk about, but I think maybe https://www.intercom.com/help/en/articles/2361922-intercom-messenger-cookies documents this instead?

[DamonFstr]

@pieterocp Apologies we've likely done several doc re-orgs since that was added to the readme.

It's referenced here - https://developers.intercom.com/installing-intercom/web/attributes-objects#messenger-attributes.

Effectively it controls the timestamp on the intercom-session-[workspace.id] cookie, a new one is sent to a messenger user on every successful ping but customers will often tie it back to their own application session timeout so a user isn't inadvertently still logged into the messenger but out of the app if for example they close their browser or whatever.

We definitely need to do a readme update.