Add documentation how to build plugin
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
new file mode 100644
index 0000000..fbd7483
--- /dev/null
+++ b/src/main/resources/Documentation/build.md
@@ -0,0 +1,28 @@
+Build
+=====
+
+This plugin is built with Buck.
+
+Only in Gerrit tree build mode is supported.
+
+Build in Gerrit tree
+--------------------
+
+Clone or link this plugin to the plugins directory of Gerrit's source
+tree, and issue the command:
+
+```
+ buck build plugins/gerrit-oauth-provider
+```
+
+The output is created in
+
+```
+ buck-out/gen/plugins/gerrit-oauth-provider/gerrit-oauth-provider.jar
+```
+
+This project can be imported into the Eclipse IDE:
+
+```
+ ./tools/eclipse/project.py
+```
