SVG and Iconography guidelines for Add-ons

[Alecaddd]

We should implement an "Iconography" section in the Add-ons category to help add-ons developers properly create or select images and SVGs for their add-ons.

These are the areas we should highlight:

• Create SVGs for toolbar buttons
• HiDPI PNGs
• Recommended software for image creation

I'll create a PR with this section later next week.

[CardBook]

any news on this ? (I'm very interested for creating a new icon for CardBook ;O)

[Alecaddd]

@CardBook I'm working on it, sorry for the lack of updates but I've been super buys with core issues.