Add ability to show block title over the border about lipgloss

[eugener]

This is pretty similar to what I had to implement within the app I'm working on.
Addition of Title API to styles would make it no-brainer. Title colors and horizontal alignment (left, center,right) would be a welcome addition too!

[meowgorithm]

Thanks @eugener. I’m on holiday for the next few weeks and will look at it when I’m back. I do think this is a common enough request that we should accommodate it.

[meowgorithm]

Implementation specifics aside, this seems like a good addition, though it may also be better off as a standalone component. If we were to add it to the library we'd also need to be able to set colors as well as the option to have both a top and bottom label simultaneously, and potential horizontal padding on the label.

If this is something you need right now here's a basic implementation you can start from: https://gist.github.com/meowgorithm/1777377a43373f563476a2bcb7d89306

[eugener]

@meowgorithm Please take a look at related PR #97. Hopefully, with few iterations, this API can become a part of the library

[greenm01]

I would also like to add a title to my border, similar to TermUI:
https://raw.githubusercontent.com/gizak/termui/master/_assets/demo.gif

Thanks!