* Update changelog, readme and version number for HAL 0.5.0 release
* Bump HAL version in BSP deps
* Point ws2812-pio and i2c-pio-rs at hal_0.5.0 branches
* Update changelog with latest commits and release date
* Update BSP authors to include 'rp-rs developers'
* Update BSP readme's to reflect current release version
* Update BSP changelogs
* Fix version number in HAL README
Somehow we already had a bunch of commits talking about 0.3.0, but it
was never released. Hence why this maybe doesn't change as many version
numbers as you might expect.