Adhering to style guide around blank lines

Added example for checking out a pull request locally.

Author: maxhild

content/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally.md

@@ -70,7 +70,9 @@ Anyone can work with a previously opened pull request to continue working on it,
    ```shell
    git fetch origin pull/ID/head:BRANCH_NAME
    ```
+   
    For pull request #123, creating a local branch named `test_branch`, this would become:
+   
    ```shell
    git fetch origin pull/123/head:test_branch
    ```