Merge pull request #6846 from tekktrik/dev/fix-uart-docs

Fix UART documentation

Author: microdev1

shared-bindings/busio/UART.c

@@ -222,15 +222,16 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_uart___exit___obj, 4, 4, busio_
 
 //|     def readline(self) -> bytes:
 //|         """Read a line, ending in a newline character, or
-//|            return None if a timeout occurs sooner, or
-//|            return everything readable if no newline is found and timeout=0
+//|         return ``None`` if a timeout occurs sooner, or
+//|         return everything readable if no newline is found and
+//|         ``timeout=0``
 //|
 //|         :return: the line read
 //|         :rtype: bytes or None"""
 //|         ...
 //|
 
-//|     def write(self, buf: WriteableBuffer) -> Optional[int]:
+//|     def write(self, buf: ReadableBuffer) -> Optional[int]:
 //|         """Write the buffer of bytes to the bus.
 //|
 //|       *New in CircuitPython 4.0:* ``buf`` must be bytes, not a string.