use cases: add checkout output

per #1054 (comment)

content/docs/use-cases/shared-development-server.md

@@ -96,7 +96,7 @@ manually. After this, they could decide to continue building this
 ```dvc
 $ git pull
 $ dvc checkout
-  # Data is linked from cache to workspace.
+A       raw  # Data is linked from cache to workspace.
 $ dvc run -d clean -o processed ./process.py clean process
 $ git add processed.dvc
 $ git commit -m "process clean data"
@@ -108,4 +108,5 @@ And now you can just as easily make their work appear in your workspace with:
 ```dvc
 $ git pull
 $ dvc checkout
+A       processed
 ```

content/docs/use-cases/versioning-data-and-model-files.md

@@ -92,6 +92,8 @@ file. Let's consider the full checkout first. It's quite straightforward:
 ```dvc
 $ git checkout v1.0
 $ dvc checkout
+M       images
+M       model.pkl
 ```
 
 These commands will restore the workspace to the first snapshot we made - code,
@@ -105,8 +107,9 @@ the previous dataset only, we can do something like this (make sure that you
 don't have uncommitted changes in the `data.dvc`):
 
 ```dvc
-$ git checkout v1.0 data.dvc
-$ dvc checkout data.dvc
+$ git checkout v1.0 images.dvc
+$ dvc checkout images.dvc
+M       images
 ```
 
 If you run `git status` you will see that `data.dvc` is modified and currently