Add Issuu icon

[PeterShaggyNoble]

First PR here; hopefully I've done this right.

Issue: #1729

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

See #1729 for a discussion on the chosen colour.

[ericcornelissen]

Very nice @PeterShaggyNoble, a perfect Pull Request 👌 Thanks for working on this!

[PeterShaggyNoble]

Looking at #1718: are unspaced 0s causing issues in some software? If so then the path data for this will need to be updated.

[ericcornelissen]

are unspaced 0s causing issues in some software? If so then the path data for this will need to be updated.

This is probably not the only SVG in recent contributions that have the same issue as #1718. I still need to investigate what exactly is causing the problem in the software and even then the solution is probably going to be with SVGO and/or SVGOMG. If people use SVGOMG the problem from #1718 is likely to occur, if you use SVGO through our local command (i.e. npm run svgo -- icons/file.svg then it should now work correctly).

Anyway, I was planning on just manually optimizing each new icon in v1.18.0 using the command I just mentioned in a single commit. As long as Hacktober is going on (and a bunch of not-very-experience people start contributing) and we have no way to determine what SVGs are problematic and which are not I'm not going to request people to change things if our current CI system approves the PR.

PS. if you want to investigate the problem further, the problem also occurs when building https://github.com/simple-icons/simple-icons-font with SVGs that cannot be loaded by Adobe Illustrator. That is perhaps an easier (cheaper) way to figure out what in the SVGs is causing the issue. Whatever way you investigate this, it must be related to the noSpaceAfterFlags option in SVGOs convertPathData plugin.