Optimize SVG files

[yoanmalie]

Optimized with https://jakearchibald.github.io/svgomg/

Before : 63 667 bytes (86 kb on disk)

After : 24 317 bytes (45 kb on disk)

All options are checked except :

• Prefer ViewBox to width/height
• Remove raster images
• Remove ViewBox
• Remove XML instructions

I think we can go deeper but it's a good first step atm.

[phated]

Woot! Thanks @yoanmalie!