More fixes to the docs. (#149)

Author: almarklein

docs/start.rst

@@ -127,7 +127,7 @@ Async
 -----
 
 A render canvas can be used in a fully async setting using e.g. Asyncio or Trio, or in an event-drived framework like Qt.
-If you like callbacks, ``loop.call_later()`` always works. If you like async, use ``loop.add_task()``. Event handlers can always be async.
+If you like callbacks, ``loop.call_later()`` always works. If you like async, use ``loop.add_task()``.
 
 If you make use of async functions (co-routines), and want to keep your code portable across
 different canvas backends, restrict your use of async features to ``sleep``  and ``Event``;

from_wgpu_canvas.md

@@ -21,10 +21,9 @@ This document lists all the changes w.r.t. the last version of the canvas in wgp
 * Bitmap rendering via builtin`canvas.get_bitmap_context()`.
 * Handling of sigint (ctrl+c).
 * Support for Trio.
-* Support for async event handlers.
 * Support for running async functions via `loop.add_task()`.
 * Simpler Qt lib selection with `from rendercanvas.pyside6 import RenderCanvas`.
-* Generic scheduling system with modes "ondemand", "continious", "fastest".
+* Generic scheduling system with modes "ondemand", "continuous", "fastest".
 
 
 ## By example