dev-plugins: Fix formatting of "Getting Started" section

Change-Id: Id3d78afb3f396c6b755f30f651e359981d4205f2
diff --git a/Documentation/dev-plugins.txt b/Documentation/dev-plugins.txt
index 9a289e1..f36fcb3 100644
--- a/Documentation/dev-plugins.txt
+++ b/Documentation/dev-plugins.txt
@@ -27,14 +27,14 @@
 
 To get started with the development of a plugin clone the sample
 plugin:
-+
-This is a project that demonstrates the various features of the
-plugin API. It can be taken as an example to develop an own plugin.
-+
+
 ----
 $ git clone https://gerrit.googlesource.com/plugins/cookbook-plugin
 ----
-+
+
+This is a project that demonstrates the various features of the
+plugin API. It can be taken as an example to develop an own plugin.
+
 When starting from this example one should take care to adapt the
 `Gerrit-ApiVersion` in the `BUILD` to the version of Gerrit for which
 the plugin is developed.