add Adafruit Macropad macros

[mutantbob]

Add a bunch of macros in the adafruit-macropad board crate to make it easier to construct working peripheral objects.

With this patch your main() can start like this:

let mut pac = pac::Peripherals::take().unwrap();
let core = pac::CorePeripherals::take().unwrap();
let mut watchdog = Watchdog::new(pac.WATCHDOG);
let clocks = macropad_clocks!(pac, watchdog);
let mut delay = cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().integer());
let pins = macropad_pins!(pac);
let timer = Timer::new(pac.TIMER, &mut pac.RESETS);
//
let mut disp = macropad_oled!(pins, clocks, delay, pac);
let mut led_pin = pins.led.into_push_pull_output();
let mut neopixels = macropad_neopixels!(pins, clocks, timer, pac);
//
let mut rotary = macropad_rotary_encoder!(pins);
let keys = macropad_keypad!(pins);

[mutantbob]

I could use some help figuring out how to make the CI checks pass. It looks like cargo test --doc --target x86_64-unknown-linux-gnu is malfunctioning.

if I remove the code sample from the top of macro.rs the test passes fine, but then the user of the library will not be able to benefit from the example.

[jannic]

You could add the ignore attribute to the code block. https://doc.rust-lang.org/rustdoc/write-documentation/documentation-tests.html#attributes That way, it stays part of the documentation, but won't be run as a doc test.

[ithinuel]

This PR should be moved to https://github.com/rp-rs/rp-hal-boards. I am closing it here but be assured these changes would be welcome over there :) .