Would love to know where I can find a database diagram which shows the relationship between table and fields, does it exist?
Also where for example can I find info about values in the share table, share_type vaules like below?
0 =
1 =
2 =
The source 
Not to be mean, but there is not so much of an up-to-date documentation, but I might be wrong and looked at the wrong place the whole time
No, does not exist atm. Also since the “database” is split over multiple apps, it would be kind of hard to do that.