Add PostCSS icon (#2758)

[phatbhoy67]

Issue: Close #2758

Checklist

• I updated the JSON data in _data/simple-icons.json
• I optimized the icon with SVGO or SVGOMG
• The SVG viewbox is 0 0 24 24

Description

Source is official svg found in the front page of the PostCSS website.

Hex value #DD3A0A is from the svg.

[PeterShaggyNoble]

This is coming in a 24.001 wide, @phatbhoy67, and it's also missing some of the detail from the 3rd path in the original (the white bits in the 12x comparison below).

[phatbhoy67]

Hey @PeterShaggyNoble, think I have fixed both issues now.

[PeterShaggyNoble]

I think you might need to up the precision on it as well, @phatbhoy67 - I'm seeing some small differences in some of the finer detail. For example, from the bottom of the triangle's left edge (original in black):

There's also a very thin line running through the bottom right quarter, which is also present in the original, that we might want to fix:

[phatbhoy67]

Line removed @PeterShaggyNoble and precision 4.

[PeterShaggyNoble]

SVG looks spot on to me now, @phatbhoy67 - nice work 👍

Although, when I open it, it's not on the canvas. Could be Inkscape playing silly-buggers on me but I'll let one of the other @simple-icons/maintainers throw an eye over it just in case.

[PeterShaggyNoble]

Restarted Inkscape and all is fine now so gonna go ahead and merge this in.