Update Btop/Activity theme - #454

I noticed that btop does not always install its conf file (ref) and consequently changing the theme via sed fails.
I forced its creation during installation and updated the related scripts.

This is great! I didn't know that btop could be styled. But it seems like only Tokyo Night looks perfect. It's using the same bg color all the way:

Whereas the other themes have different inner background and outer background:

All the themes should share the same background with the padding.

@dhh
Yes, I noticed.
I saw that the btop styles are already fixed, however to further align we can set in btop.conf:

theme_background = False

So that the btop panel can maintain the transparency of Alacritty.

Let's try it.

@dhh
I tested with all the themes and it actually applies transparency.
With most of the themes, the change has little impact on the display since the background applied by Btop is slightly darker than that of Alacritty, but with the Gruvbox theme the difference is more evident.

Without trasparency:

With transparency:

Ah, I think that part was already fixed by the changes I did. I was hoping that it would actually make the whole thing transparent, so you could peak at the background image.

Ah, I think that part was already fixed by the changes I did. I was hoping that it would actually make the whole thing transparent, so you could peak at the background image.

Mh, it adds transparency, but obviously it is based on the one set on Alacritty and it might not always be evident in fact.

Even trying it on rose-pine with a more marked background some outlines are visible, but not much.