RP2040 isn't used in the Packages example (anymore?)

[robotskirts]

Layout section references the RP2040 in the previous section. But there's no RP2040 info there.

docs/atopile/essentials/5-layout.mdx

Line 25 in 18d7d55

If you import the `rp2040` module installed in the [previous section](./4-packages), you can reuse its layout.