Add navigation theme documentation

doc/user/profile/preferences.md

@@ -7,6 +7,34 @@ To navigate to your profile's preferences, click your avatar icon in the top
 right corner and select **Settings**. From there on, choose the **Preferences**
 tab.
+![Profile preferences settings](img/profile_settings_dropdown.png)
+
+## Navigation theme
+
+>**Note:**
+Navigation themes have been re-introduced with [GitLab 10.0](https://about.gitlab.com/2017/09/22/gitlab-10-0-released/).
+
+The GitLab navigation theme setting allows you to personalize your GitLab experience.
+You can choose from several color themes that add unique colors to the top navigation
+and left side navigation.  
+Using individual color themes might help you differentiate between your different
+GitLab instances.
+
+The default palette is Indigo. You can choose between 10 different themes:
+
+- Indigo
+- Light Indigo
+- Blue
+- Light Blue
+- Green
+- Light Green
+- Red
+- Light Red
+- Dark
+- Light
+
+![Profile preferences syntax highlighting themes](img/profile-preferences-syntax-themes.png)
+
 ## Syntax highlighting theme
 >**Note:**
@@ -16,7 +44,7 @@ list of supported languages visit the rouge website.
 Changing this setting allows you to customize the color theme when viewing any
 syntax highlighted code on GitLab.
-The default one is **White**, and you can choose among 5 different colors:
+The default syntax theme is White, and you can choose among 5 different colors:
 - White
 - Dark
@@ -24,6 +52,8 @@ The default one is **White**, and you can choose among 5 different colors:
 - Solarized dark
 - Monokai
+![Profile preferences navigation themes](img/profil-preferences-navigation-theme.png)
+
 ## Behavior
 The following settings allow you to customize the behavior of GitLab's layout
@@ -52,16 +82,16 @@ You have 8 options here that you can use for your default dashboard view:
 - Assigned Issues
 - Assigned Merge Requests
-### Project home page content
-The project home page content setting allows you to choose what content you want to
+### Project overview content
+The project overview content setting allows you to choose what content you want to
 see on a project’s home page.
 You can choose between 3 options:
-- Show the files and the readme (default)
-- Show the readme
-- Show the project’s activity
+- Files and Readme (default)
+- Readme
+- Activity
 [rouge]: http://rouge.jneen.net/ "Rouge website"
 [todos]: ../../workflow/todos.md