Updates nrf-hal version to 0.14.0 to resolve dependency conflicts. (#57)

README.md

@@ -93,7 +93,7 @@ For the nRF52840 you'll want to use the [`nrf52840-hal`].
  # Cargo.toml
  [dependencies]
 -# some-hal = "1.2.3"
-+nrf52840-hal = "0.12.0"
++nrf52840-hal = "0.14.0"
 ```
 
 #### 5. Import your HAL