Subtree 1.19 merged in docs

Signed-off-by: Lunny Xiao <xiaolunwen@gmail.com>

versioned_docs/version-1.19/usage/pull-request.en-us.md

@@ -0,0 +1,31 @@
+---
+date: "2018-06-01T19:00:00+02:00"
+title: "Pull Request"
+slug: "pull-request"
+sidebar_position: 13
+toc: false
+draft: false
+menu:
+  sidebar:
+    parent: "usage"
+    name: "Pull Request"
+    sidebar_position: 13
+    identifier: "pull-request"
+---
+
+# Pull Request
+
+## "Work In Progress" pull requests
+
+Marking a pull request as being a work in progress will prevent that pull request from being accidentally merged. To mark a pull request as being a work in progress, you must prefix its title by `WIP:` or `[WIP]` (case insensitive). Those values are configurable in your `app.ini` file :
+
+```ini
+[repository.pull-request]
+WORK_IN_PROGRESS_PREFIXES=WIP:,[WIP]
+```
+
+The first value of the list will be used in helpers.
+
+## Pull Request Templates
+
+You can find more information about pull request templates at the page [Issue and Pull Request templates](issue-pull-request-templates).