[Feature Request] support generating patterns

[renzhamin]

When we want to generate data ourselves, there is usually a particular use case in mind.
Thats why generating certain patterns would be very useful
For example, I want to generate data that resembles a license plate. such as "city - A 12-3451".

The pattern input should be similar to regex as people are already familiar with it.
In my previous example the pattern would be something like '\w - [ABCD] [0123456789]{2}-[0123456789]{4}'