Add GitHub Icons

[Av32000]

Added icons for special Github folders:

• .github
• workflows
• ISSUE_TEMPLATE

[Comdec35000]

Hey !
First of all, thanks for your contribution, i'll merge it later, but first, I need you to make some modifications. The icons of the theme folows some very specific color code. The icons can only have some of these colors :
White : D6E0E3
Black : 524E5A
Red : FF4D35
Orange : FFA800
Gold : FFD600
Lime : AFED00
Green : 00E878
Pink : FF47B5
Purple : B339EC
Indigo : 8710FF
Blue : 2B66FF
Cyan : 2EB4FF
Turquoise : 00F3C8

This is to ensure visual consitency and to make the icons readable on light and dark theme.
I'll merge your PR when this change will be made.
Thanks you and have a nice day

[Av32000]

Hi !
I just changed the colors of the icons to match the color code of the extension. Here are the new icons :

Thanks you and have a nice day