circuit-json supports polygon pcb smtpads, but there isn't an example in the docs

https://github.com/tscircuit/circuit-json/blob/main/src/pcb/pcb_smtpad.ts

• Create a tscircuit/core pcb snapshot test demonstrating polygon smtpads with solder mask work
• PR to tscircuit/props to add any needed properties to allow tscircuit/core to create polygon smtpads with solder mask e.g. <smtpad coverWithSolderMask />
• PR to circuit-json to make sure pcb smtpads have property covered_with_solder_mask
• PR to tscircuit/circuit-to-svg to add support for drawing pads that are covered by solder mask (optionally with flag) Add support for rendering soldermask part of SVG (if showSolderMask: true) circuit-to-svg#314
• PR to tscircuit/docs with how tutorial describing how to create a capacitive touch element

A design like this is a good idea for the docs to demonstrate the concept, since it's relatively common

/bounty $150