Scrolling text box widget feature: Stick to the bottom

[HisenZhang]

Is your feature request related to a problem? Please describe.
Simply found this feature might be handy when people want to display logging in UI.

Describe the solution you'd like
A scrolling text box always sticks to the bottom (latest line). For example, the Minecraft Java server has a log widget showing what's going on with the server.

I have hacked py-cui for this purpose in my project by dynamically injecting methods into the py-cui object, which is not elegant (yet simple.....) But codes may be reused for this feature improvement.

Additional context
Like this log console to the right:

[jwlodek]

Sure that sounds useful! If you wanted to make a PR for that that would be appreciated, if not I can probably work on it sometime

[HisenZhang]

I can have a try... As a student who only worked on school projects before this is a good opportunity. Correct me if I did something wrong.