Add subtitles to build documentation

Change-Id: I1fb83b3c49b15109c8aaaa04deee23c4134ca7a4
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 4c56ed6..52180d9 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -10,7 +10,7 @@
 The standalone build mode is recommended, as this mode doesn't require
 the Gerrit tree to exist locally.
 
-
+### Build standalone
 
 Clone bucklets library:
 
@@ -43,6 +43,7 @@
   buck-out/gen/@PLUGIN@.jar
 ```
 
+### Build in Gerrit tree
 
 Clone or link this plugin to the plugins directory of Gerrit's source
 tree, and issue the command: