Add transparent background to the powerline

[Heyian]

I've tried to create the least possible if statements to achieve this. This should solve #101

I've added the 2 following options:

1. @dracula-transparent-powerline-bg -> Default to false, set background transparency on the powerline
2. @dracula-inverse-divider -> I had to change the divider for the window panes because I couldn't get the foreground color to be transparent, only the backgroud. So I've set this inversed divider to be used if transparent-powerline-bg is set to true. I've added it to the options so the user could use another divider if he had decided to change the show-left-sep

I've added some new variables :

1. bg_color -> set the backgroud color
2. window_sep_fg -> set the foreground color of the windows separator (it is necessary to change it if we use the inversed divider)
3. window_sep_bg -> set the background of the windows separator, same reasons as window_sep_fg
4. window_sep -> sets the divider used between the windows.

Those variables and their placement in the code allows no other if statement than setting those variables. I've tried to name the variables with something similar that was already used.

I've checked the powerline with transparent-powerline-bg set as false or without using it in tmux.conf and I can't find any differences from the original code.

This change doesn't seem to break anything. I haven't touched the right side of the bar since it seemed to be filled. I don't use much plugins though but I've tested it with ssh-session, git and playerctl and I can't find anything that breaks.

[ethancedwards8]

Can you attach screenshots? I'm not sure I'm getting the intended effect using Kitty on MacOS.

EDIT: Nevermind, I had a typo. Everything LGTM. Thank you so much! This is amazingly clean code.

[ethancedwards8]

My only concern is this little circle in the lower left hand corner. Can you reproduce?

[Heyian]

First of all, thanks for the comment about my code, it made my day!

I can't reproduce the little circle. I've tried with the smiley instead of the session and it doesn't seem to make any changes. Here's what it looks like on my kitty.

It seems the wrong nerd font icon get's loaded on your end. If you look at the sh file, do you see the right icon if you look at the show_inverse_divider variable? I'm using the icon nf-ple-left_hard_divider_inverse if it helps.

Here's what it looks like in my nvim :

[ethancedwards8]

You are right. It seems to be an issue on my end. I'm going to do some more review, then I'll probably merge. Thank you for your contribution!