Space gets displayed incorrectly

[dderjoel]

When I was using this project with the Iconic Fonts (Font Awesome 5), I had the space-char rendered incorrectly looking like this.

Apparently, this is related to Pango as mentioned here, but the fix somehow did not work.
Anachron/i3blocks#53

However, using a workaround of having a transparent space (or any other char), has the same effect.
I changed https://github.com/mh21/i3-renameworkspaces/blob/master/i3-renameworkspaces.pl#L64
from
$newname = join(': ', $num, join(' ', @{$$ws{'windows'}}) || ());
to
$newname = join(': ', $num, join('<span foreground=\'#00000001\'> <span>', @{$$ws{'windows'}}) || ());

Please consider adding a comment above this line which mentions this issue/workaround.

Also, a note in the readme file referring to the PangoMarkupFormat which is available, would be helpful.