[Feature Request] always show scrollbars

It would be really nice if scrollbars were always displayed.

Adding 'gtk-overlay-scrolling=0' to /usr/share/themes/Chicago95/gtk-3.0 seems to do the trick:

```
lee@an17 /usr/share/themes/Chicago95/gtk-3.0
$ cat settings.ini
[Settings]
gtk-auto-mnemonics = 0
gtk-visible-focus = automatic
gtk-menu-images = true
gtk-primary-button-warps-slider = false

gtk-overlay-scrolling=0
# LR: 0: always show scrollbars 1: hide the scrollbar until a mouseover
# https://blog.gtk.org/2017/10/11/a-scrolling-primer/
# We expect touchpad (or track point) scrolling to be one of the most common forms of scrolling,
# and the scrollbar operates as a narrow indicator for this.
# in other words, this is why the scrollbar is so useless in current themes.

```