feat: add osc transparency options

[Hellboy00000]

Add two new options:

• fade_transparency_strength
• window_fade_transparency_strength

This adds more customization to the fade options and can be used to create a transparency box for the top and bottom of the OSC.

Edit: Config settings example

Botton box

# alpha of the OSC background box 
# This sets the size of the box. The higher the number, the larger the box
fade_alpha=80
# blur strength for the OSC alpha fade. caution: high values can take a lot of CPU time to render
# Set this to 0 to create the box
fade_blur_strength=0
# use with "fade_blur_strength=0" to create a transparency box
# This sets the amount of transparency
fade_transparency_strength=75

Top box

# alpha of the window title bar (0 to disable)
# This sets the size of the box. The higher the number, the larger the box
window_fade_alpha=152
# blur strength for the window title bar. caution: high values can take a lot of CPU time to render
# Set this to 0 to create the box
window_fade_blur_strength=0
# use with "window_fade_blur_strength=0" to create a transparency box
# This sets the amount of transparency
window_fade_transparency_strength=75

[Samillion]

Great work, thank you very much.

If I may, in the PR post, could you include an example config on creating a box. So that others can refer to the PR for reference in the future.

[Hellboy00000]

@Samillion

I added an example of the configuration with a small explanation.

[Samillion]

Much appreciated.