Merge branch 'default-label-documentation' into 'master'

Clarify the features for generating default label sets

## What does this MR do?

* Split out the information regarding the label set that GitLab can generate
* Add information for the labels view in the Admin panel

## Are there points in the code the reviewer needs to double check?

* Please ensure that the newly added section relating to the Admin area seems relevant
* Please verify adherence to the documentation styleguide

## Why was this MR needed?

Documentation regarding default label sets was missing

## What are the relevant issue numbers?
Closes #1865

See merge request !5736

doc/user/admin_area/labels.md

+# Labels
+
+## Default Labels
+
+### Define your own default Label Set
+
+Labels that are created within the Labels view on the Admin Dashboard will be automatically added to each new project.
+
+![Default label set](img/admin_labels.png)

doc/user/project/labels.md

@@ -22,26 +22,38 @@ created yet.
 
 ![Generate new labels](img/labels_generate.png)
 
+Creating a new label from scratch is as easy as pressing the **New label**
+button. From there on you can choose the name, give it an optional description,
+a color and you are set.
+
+When you are ready press the **Create label** button to create the new label.
+
+![New label](img/labels_new_label.png)
+
 ---
 
-You can skip that and create a new label or click that link and GitLab will
-generate a set of predefined labels for you. There 8 default generated labels
+## Default Labels
+
+It's possible to populate the labels for your project from a set of predefined labels.
+
+### Generate GitLab's predefined label set
+
+![Generate new labels](img/labels_generate.png)
+
+Click the link to 'Generate a default set of labels' and GitLab will
+generate a set of predefined labels for you. There are 8 default generated labels
 in total and you can see them in the screenshot below.
 
 ![Default generated labels](img/labels_default.png)
 
 ---
 
-You can see that from the labels page you can have an overview of the number of
-issues and merge requests assigned to each label.
-
-Creating a new label from scratch is as easy as pressing the **New label**
-button. From there on you can choose the name, give it an optional description,
-a color and you are set.
+## Labels Overview
 
-When you are ready press the **Create label** button to create the new label.
+![Default generated labels](img/labels_default.png)
 
-![New label](img/labels_new_label.png)
+You can see that from the labels page you can have an overview of the number of
+issues and merge requests assigned to each label.
 
 ## Prioritize labels