[feature request] Support association types for ER model

[j796160836]

Thanks for this awesome project! I use it to draw use case diagram and Entity-relationship model (ER model). I found that it seems lack one to one, one to many and many to many association types. Like this ER diagram:

I hope it can support. Thanks again.

[j796160836]

Here is some workaround to draw ER diagram (ERDs). Use text after association types. Like this:

[ Order | 
🔑 OrderID : varchar(20) <PK>;
CompanyName : varchar(20);
CreateTime : timestamp ]

[ OrderDetail |
🗝️ OrderID : varchar(20) <FK>;
ItemName : varchar(20) ;
Quantity : Int ;
Price : Int ]

[ Order ] - 1...n [ OrderDetail ]

[skanaar]

Please see #185

I would like to implement ER diagrams. Just hard to find the time :)

[skanaar]

Closed as duplicate of #185