Is your feature request related to a problem? Please describe.
Hi Jonathan!
Is it possible to create irragular shaped fare zones for a station? In current situation, fare zone of a station is always a simple rectangle. However, there are cases that a small station (i.e. fare zone, with a different number) have to be placed inside a larger one, such as when:
可以添加绘制不规则形状收费区的功能吗？现在收费区只能是一个矩形，一个地点可能对应两个以上收费区，费用无法被精确控制：

1. The station is an interchange station of routes operated by different companies implementing different fee standards.
   一个换乘站有两个公司的线路经过，执行不同收费标准；
2. Special situations, such as I wish to add a "pay upon arrival" office in a station, ticket evaders are expected to tap the card here before going through the exit gate (to avoid paying the heavy fine).
   还有一些特殊情况，比如希望在中心车站做一个补票处，如果乘客未记录进站，在这里出站时就可以先刷一下卡视作进站之后再出站，以免被收取高额罚款。
   

In those cases, overlapped fare zones cause problems. The amount of fee charged is uncontrollable.
如果收费区重叠，那费用就不可控，有时按外层收费区计费，有时按内层收费区计费，造成混乱。

If irragular shaped fare zone (i.e. station territory) could be drawn when creating a station, overlaps could be avoided.
希望能加入画不规则形状车站范围的功能，这样就能避免重叠带来的混乱。

I'd be appreciated if this feature could enventually be added.
非常感谢！

Describe the solution you'd like
The problem might get solved by one of the following paths:

1. Free curves are allowed to be drawn while creating a fare zone.
   可以随意画一条曲线围成收费区。
   

2. Multiple rectangles are allowed to be drawn simultaneously to make up a whole fare zone.
   可以同时画多个矩形组成一个完整的收费区。
   

Additional Information
Add any other context or screenshots about the feature request here.

OK