Fix broken images in tutorial.md, resolve #579

docs/tutorial.md

@@ -16,40 +16,40 @@ Below is a JSON file containing lots of science fictions description with differ
 
 We need to create a new project for this task. Logging in with the superuser account. 
 
-![projects](https://camo.githubusercontent.com/aafdc69f37af26940a6c16a49c0b9387eed555ea/68747470733a2f2f7773312e73696e61696d672e636e2f6c617267652f303036744e62527767793166796a767977736d79346a33316b793073347162622e6a7067)
+![Sign in as a superuser.](./images/signin.png)
 
-To create your project, make sure you’re in the project list page and click `Create Project` button. As for this tutorial, we name the project as `sequence labeling for books`, write some description, choose the sequence labeling task type.
+To create your project, make sure you’re in the project list page and click `Create` button. As for this tutorial, we name the project as `sequence labeling for books`, write some description, choose the sequence labeling task type.
 
-![](https://camo.githubusercontent.com/4f5dd3e39d21ea37dc98d8a6fb5c7b70cb721490/68747470733a2f2f7773342e73696e61696d672e636e2f6c617267652f303036744b6654636779316731377a6132306676386a3330686a306438676c6c2e6a7067)
+![Creating a project.](./images/create_project.png)
 
 
 ## Import Data
 
-After creating a project, we will see the "Import Data" page, or click `Import Data` button in the navigation bar. We should see the following screen:
+After creating a project, we will see the `Dataset` page, and click `Import dataset` button in the `Actions` menu. We should see the following screen:
 
-![](https://camo.githubusercontent.com/ecf6ef63f9a4684d12f293f3e9c7655280fb6636/68747470733a2f2f7773342e73696e61696d672e636e2f6c617267652f303036744b6654636779316731377a3133696835356a33306c753063307133302e6a7067)
+![Importing a dataset.](./images/import_dataset.png)
 
-We choose `JSONL` and click `Select a file` button. Select `books.json` and it would be loaded automatically. 
+We choose `JSON` and click `Select a file` button. Select `books.json` and it would be loaded automatically. 
 
 ## Define labels
 
 Click `Labels` button in left bar to define our own labels. We should see the label editor page. In label editor page, you can create labels by specifying label text, shortcut key, background color and text color.
 
-![tutorial_label_editor](https://camo.githubusercontent.com/4864de4f937b46aec9ddef10bd1e19ec607b469a/68747470733a2f2f7773322e73696e61696d672e636e2f6c617267652f303036744e62527767793166796a773531636e72796a33316d743075303735392e6a7067)
+![Defining labels.](./images/define_labels.png)
 
 As for the tutorial, we created some entities related to science fictions.
 
 ## Annotation
 
-Next, we are ready to annotate the texts. Just click the `Annotate Data` button in the navigation bar, we can start to annotate the documents.
+Next, we are ready to annotate the texts. Just click the `Start annotation` button in the navigation bar, we can start to annotate the documents.
 
-![tutorial_annotation](https://camo.githubusercontent.com/fb1384fdacf5ec153d05bd34846aa485764dbbf8/68747470733a2f2f7773312e73696e61696d672e636e2f6c617267652f303036744e62527767793166796a773676363834726a3331723330753074626a2e6a7067)
+![Annotating named entities.](./images/annotation.png)
 
 ## Export Data
 
-After the annotation step, we can download the annotated data. Click the `Edit data` button in the navigation bar, and then click `Export Data`. You should see below screen:
+After the annotation step, we can download the annotated data. Go to the `Dataset` page and click the `Export dataset` button in the `Action` menu. After selecting an export format, click `Export`. You should see below screen:
 
-![](https://camo.githubusercontent.com/9c53ee432efa035a5c10f9c938c956bc6b8eb697/68747470733a2f2f7773342e73696e61696d672e636e2f6c617267652f303036744b6654636779316731377a35746b3930786a33306d333063317765692e6a7067)
+![Exporting a dataset.](./images/export_dataset.png)
 
 Here we choose JSONL file to download the data by clicking the button. Below is the annotated result for our tutorial project.