move hidden into module

[burrbull]

cc @rust-embedded/tools

[thejpster]

v0.29: https://docs.rs/rp2040-pac/latest/rp2040_pac/

This patch:

[thejpster]

I like these changes. But I wonder if there's also scope to try and add some information to this page:

Edit:

Perhaps like:

[burrbull]

@thejpster Now it looks like and accordingly.

[thejpster]

Can we remove the '\n' between the lines? If they have '\n' between them I think they should be a bulleted list. Otherwise I think it should be one paragraph with no new-lines in it.

i.e.

You can read this register and get somemod::R. You can reset, write, write_with_zero this register and get somemod::W. You can also modify this register.

rather than

You can read this register and get somemod::R.
You can reset, write, write_with_zero this register and get somemod::W. 
You can also modify this register.

I also propose expanding on See API a little bit.

But these are minor things really. I really like these changes!

[burrbull]

done

[thejpster]

LGTM. Ship it.

[thejpster]

So good I managed to approve it twice :/