Use decimals for greater shape control and accuracy

@bennettfeely Absolutely LOVE Clippy, I use it all the time for projects, it's an essential tool. Thank you for building it and offering it to the community!

Recently I was working on a project where I needed my polygon shape's sides to be exactly like a mockup, but I wasn't able to get the precision I needed in Clippy. I did end up using Clippy, but then had to edit the final CSS, by adding decimals. For example, 95% 51% would be 95.2% 51%.

I would be curious to know how challenging it would be to make the numbers increment by 0.1 rather than increments of 1. This would mean precise control for more nuanced custom polygon shapes would be easier to produce in Clippy.