minor doc changes

doc/user_guide.adoc

@@ -122,12 +122,12 @@ jlink {
     ...
 }
 ----
-|===
 
 For a project named `hello`, executing the `jlinkZip` task with the above configuration, and assuming default values for the other properties,
 the plugin will generate the platform-specific images in the directories
 `build/image/hello-linux-x64` and `build/image/hello-linux-s390x`.
 The archived images will be available in `build/image-linux-x64.zip` and `build/image-linux-s390x.zip`.
+|===
 
 [maroon]##targetPlatform##(String [purple]##name##, Action<TargetPlatform> [purple]##action##):: This more powerful version of the `targetPlatform` method allows configuring the target platform parameters using a script block. +
 [purple]##**name**##: an identifier of your choice that will be appended to the `imageDir` and `imageZip` properties to
@@ -188,7 +188,6 @@ jlink {
 |===
 
 
-
 [[scriptBlocks]]
 == Script blocks