docs: fix grammatical errors

docs/dev.rst

@@ -87,7 +87,7 @@ Finally, the platform can also be started back up with ``launch``. It will take
 Debugging with breakpoints
 --------------------------
 
-To debug a local edx-platform repository, add a `python breakpoint <https://docs.python.org/3/library/functions.html#breakpoint>`__ with ``breakpoint()`` anywhere in the code. Then, start the container by running ``start -d`` followed by the service's name and then attach to the container by running ``attach`` followed by the service's name::
+To debug a local edx-platform repository, add a `python breakpoint <https://docs.python.org/3/library/functions.html#breakpoint>`__ with ``breakpoint()`` anywhere in the code. Then, start the container in detached mode by running ``start -d`` followed by the service's name and then attach to the container by running ``attach`` followed by the service's name::
 
   # Debugging LMS:
   tutor dev start -d lms