add examples

[shahin]

The package and README don't contain full-fledged examples. Add examples to make the use and operation of sequenceminer clear to a new user.

[Dobatymo]

Could you add a short example on how to use your miner with a single sequence. I have one long time series (A, B, D, E, C, A, B, A, D.....) with each event at a distinct time and want to find common patterns for finding a certain event (D) like A, B -> D
That would be very helpful.