micropython: Use separate keys for CTRL + C.

Since each :kbd: key is rendered as a button, it is more intuitive to
render them separately. (There is no CTRL-C button.)

Fixes https://github.com/pybricks/pybricks-api/issues/125

src/micropython/__init__.py

@@ -177,9 +177,9 @@ def kbd_intr(chr: int) -> None:
     """
     kbd_intr(chr)
 
-    Sets the character that raises a ``KeyboardInterrupt`` exception when
+    Sets the character that triggers a ``KeyboardInterrupt`` exception when
     you type it in the input window. By default it is set to ``3``,
-    corresponding to :kbd:`Ctrl-C`.
+    which corresponds to pressing :kbd:`Ctrl` :kbd:`C`.
 
     Arguments:
         chr (int): Character that should raise the ``KeyboardInterrupt``.

src/ubuiltins/__init__.py

@@ -1399,7 +1399,7 @@ class KeyError(LookupError):
 
 class KeyboardInterrupt(BaseException):
     """
-    Raised when the user hits the interrupt key (normally :kbd:`Control-C`).
+    Raised when the user hits the interrupt key (normally :kbd:`Ctrl` :kbd:`C`).
     """