Fill out stream cuts examples with a new case with multiple readers

[elizabethbain]

Add to Stream cut examples to show behavior of stream cuts when there are multiple readers. There is a simple stream cut example where there is a ReaderGroup with one reader and multiple streams. This can be a modification to the current stream cut example or a new example by adding multiple readers to a ReaderGroup that has a single stream

a) Getting streamcuts across multiple segments that the readers are reading from
b) Read events from the current stream cuts to the tail
c) Read all events in the stream from the Head to the available stream cuts