[Feature] Add ability to set "Submit Type" for project

By default "Submit Type" is: merge if necessary

Change-Id: Id048aad6ec30586de50821adf9b9aff88cf67fee
diff --git a/README.rst b/README.rst
index 89e6ddc..f0758b2 100644
--- a/README.rst
+++ b/README.rst
@@ -155,6 +155,7 @@
             require_change_id: true
             require_agreement: true
             merge_content: true
+            action: "fast forward only"
 
 
 .. code-block:: yaml
diff --git a/gerrit/files/project.config b/gerrit/files/project.config
index 1a5a02c..701c24b 100644
--- a/gerrit/files/project.config
+++ b/gerrit/files/project.config
@@ -15,6 +15,7 @@
 
 [submit]
 	mergeContent = {{ project.get('merge_content', True)|lower }}
+	action = {{ project.get('action', 'merge if necessary')|lower }}
 
 {#
 [capability]