Address peer review comments

Signed-off-by: Ivan Santiago Paunovic <[email protected]>

Author: ivanpauno

launch_pytest/README.md

@@ -15,7 +15,7 @@ launch_testing is an standalone testing tool, which lacks many features:
   * It's impossible to filter test cases by name and run only some.
   * It's impossible to mark a test as skipped or xfail.
   * The error reporting of the tool was custom, and the output wasn't as nice as the output
-    generated by other testing frameworks as unittest and pytest.
+    generated by other testing frameworks such as unittest and pytest.
 
 launch_pytest is a really simple pytest plugin leveraging pytest fixtures to manage a launch service lifetime easily.
 
@@ -29,7 +29,7 @@ Run the example by doing:
 python3 -m pytest test/launch_pytest/examples/pytest_hello_world.py
 ```
 
-The `launch_pytest` plugin will launch the nodes found in the `launch_descripture` fixture, run the tests from the `test_read_stdout()` class, shut down the launched nodes, and then run the statements after the `yield` statement in `test_read_stdout()`.
+The `launch_pytest` plugin will launch the nodes found in the `launch_description` fixture, run the tests from the `test_read_stdout()` class, shut down the launched nodes, and then run the statements after the `yield` statement in `test_read_stdout()`.
 
 #### launch_pytest fixtures
 
@@ -45,13 +45,14 @@ def launch_description(hello_world_proc):
     ])
 ```
 
-A `@launch_pytest.fixture` function should return a `launch.LaunchDescription` object, or a sequence of objects which first item is a `launch.LaunchDescription`.
+A `@launch_pytest.fixture` function should return a `launch.LaunchDescription` object, or a sequence of objects whose first item is a `launch.LaunchDescription`.
 This launch description will be used in all tests with a mark `@pytest.mark.launch(fixture=<your_fixture_name>)`, in this case `<your_fixture_name>=launch_description`.
 
 The launch description can include a `ReadyToTest` action to signal to the test framework that it's safe to start the active tests.
 If one isn't included, a `ReadyToTest` action will be appended at the end.
 
-launch_pytest fixtures can have `module`, `class` or `function` scope, the default is `function`.
+`launch_pytest` fixtures can have `module`, `class` or `function` scope.
+The default is `function`.
 For example:
 
 ```python