Log Message:
py-textual: update to 0.86.1.

0.86.1

Tweaks to demo

0.86.0

Adds an entirely new theming system and an updated demo

The new theming system standardizes the look-and-feel of widgets.
This should mean they will look pretty when used in combination,
and you will need less tweaking of your UI. If your app already
has a customized look and feel, you may need to make a few style
changes.