Merge SVG polygons into SVG paths to *hopefully* fix cursed rendering

[rudedogg]

I was trying to add the Zig mark as a custom SF Symbol, and the rendering didn't come out quite right. I think this is caused by using polygons instead of paths.

My hope is this PR will fix the "cursed logo rendering":

All I've done is open each logo in Affinity Designer, and select all the Polygons in each grouping, and click merge. This should have identical "visible" output, but the extra data about how the logo was constructed is now gone:

Before:

After:

[rudedogg]

This seems to have cleaned things up a little even in the Github diff:

Maybe it's specific to how they do things, but it seems like a good sign