Consider implementing auto-scrolling of the RichTextBox contents

[augustoproiete]

There seems to be a desire for AutoScrolling by a few users of the sink, @TonyValenti gave it a first pass with via #32 where the scrolling is controlling by the sink

Whilst I'm not 100% sure AutoScrolling is a job that a Serilog Sink should do, i.e. seems like this should be a responsibility of the control, it's worth discussing possible approaches and considering a follow-up PR to (perhaps) implement an extension method that enables AutoScrolling on a RichTextBox, or something along the lines of #32

[imlokesh]

I made this library for an autoscrolling log text box. I'm not very familiar with RichTextBox and its pretty basic but you might get some ideas. https://github.com/imlokesh/SerilogTextBox