[WIP] Add export density to canvas renderer

[lucasdinonolte]

• Makes canvas previews crisp on retina displays
• Allows users to choose the desired pixel density before exporting

[runemadsen]

I was just thinking about this, and I think this is the right implementation. We should make sure that the getCanvas function throws an error if it doesn't have the needed width and height, whether that comes from inputs, the getCanvas arguments, or both. A nice error message with a call for the user to add the dimensions would be very helpful.

[lucasdinonolte]

I was just thinking about this, and I think this is the right implementation. We should make sure that the getCanvas function throws an error if it doesn't have the needed width and height, whether that comes from inputs, the getCanvas arguments, or both. A nice error message with a call for the user to add the dimensions would be very helpful.

I had the same notion and added some first drafts for error messages. https://github.com/designsystemsinternational/mechanic/pull/146/files#diff-cea56d01b8f19fd6436a19f2b4bbd9d2258c6edbeef3df917df2026fcf1ed520R82 :blush: