Add documentation for manifest import feature

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

doc/api/settings.md

@@ -105,7 +105,7 @@ PUT /application/settings
 | `housekeeping_gc_period`                 | integer          | no                                            | Number of Git pushes after which 'git gc' is run.                                                                                                                                                                                                                                                                                                                                                                                                         |
 | `housekeeping_incremental_repack_period` | integer          | no                                            | Number of Git pushes after which an incremental 'git repack' is run.                                                                                                                                                                                                                                                                                                                                                                                      |
 | `html_emails_enabled`                    | boolean          | no                                            | Enable HTML emails                                                                                                                                                                                                                                                                                                                                                                                                                                        |
-| `import_sources`                         | Array of strings | no                                            | Sources to allow project import from, possible values: "github bitbucket gitlab google_code fogbugz git gitlab_project                                                                                                                                                                                                                                                                                                                                    |
+| `import_sources`                         | Array of strings | no                                            | Sources to allow project import from, possible values: "github bitbucket gitlab google_code fogbugz git gitlab_project manifest                                                                                                                                                                                                                                                                                                                           |
 | `koding_enabled`                         | boolean          | no                                            | Enable Koding integration. Default is `false`.                                                                                                                                                                                                                                                                                                                                                                                                            |
 | `koding_url`                             | string           | yes (if `koding_enabled` is `true`)           | The Koding instance URL for integration.                                                                                                                                                                                                                                                                                                                                                                                                                  |
 | `max_artifacts_size`                     | integer          | no                                            | Maximum artifacts size in MB                                                                                                                                                                                                                                                                                                                                                                                                                              |

doc/user/project/import/index.md

@@ -11,6 +11,7 @@
 1. [From SVN](svn.md)
 1. [From TFS](tfs.md)
 1. [From repo by URL](repo_by_url.md)
+1. [By uploading a manifest file](manifest.md)
 
 In addition to the specific migration documentation above, you can import any
 Git repository via HTTP from the New Project page. Be aware that if the

doc/user/project/import/manifest.md

+# Import multiple repositories by uploading a manifest file
+
+GitLab allows you to import all the required git repositories based on the 
+Android repository manifest file.
+
+You can do it by following next steps: 
+
+1. From your GitLab dashboard click **New project**
+1. Switch to the **Import project** tab
+1. Click on the **Manifest file** button
+1. Provide GitLab with a manifest xml file
+1. Select a group you want to import to (you need to create a group first if you don't have one)
+1. Click **Import projects** 
+1. You will be redirected to the import status page with projects list based on manifest file
+1. Check the list and click 'Import all repositories' to start import.
+
+![Manifest upload](img/manifest_upload.png)
+
+![Manifest status](img/manifest_status.png)
+
+### Manifest format
+
+A manifest must be an XML file. There must be one `remote` tag with `review` attribute
+that contains a URL to a git server. Each `project` tag must have `name` and `path` attribute. 
+GitLab will build URL to the repository by combining URL from `remote` tag with a project name.
+A path attribute will be used to represent project path in GitLab system. 
+
+Below is a valid example of manifest file.
+
+```xml
+<manifest>
+  <remote review="https://android-review.googlesource.com/" />
+
+  <project path="build/make" name="platform/build" />
+  <project path="build/blueprint" name="platform/build/blueprint" />
+</manifest>
+```
+
+As result next projects will be created: 
+
+| GitLab | Import URL |
+|---|---|
+| https://gitlab/YOUR_GROUP/build/make | https://android-review.googlesource.com/platform/build | 
+| https://gitlab/YOUR_GROUP/build/blueprint | https://android-review.googlesource.com/platform/build/blueprint |