Spelling fixes in docs.

Author: rwb27

docs/source/actions.rst

@@ -101,7 +101,7 @@ If you start a new thread from an action, code running in that thread will
 not have an invocation ID set in a context variable. A subclass of
 `threading.Thread` is provided to do this, `.ThreadWithInvocationID`\ .
 This may be useful for test code, or if you wish to run actions in the
-backgound, with the option of cancelling them.
+background, with the option of cancelling them.
 
 Raising exceptions
 ------------------

docs/source/structure.rst

@@ -51,4 +51,4 @@ Client code can be written in any language that supports an HTTP request. Howeve
 
 `.ThingClient` is a class that wraps up the required HTTP requests into a simpler interface. It can retrieve the :ref:`gen_td` over HTTP and use it to generate a new object with methods matching each `.thing_action` and properties matching each `.property`.
 
-While the current dynamic implemenation of `.ThingClient` can be inspected with functions like `help` at runtime, it does not work well with static tools like `mypy` or `pyright`\ . In the future, LabThings should be able to generate static client code that works better with autocompletion and type checking.
+While the current dynamic implementation of `.ThingClient` can be inspected with functions like `help` at runtime, it does not work well with static tools like `mypy` or `pyright`\ . In the future, LabThings should be able to generate static client code that works better with autocompletion and type checking.