Documentation: Add missing alternative for plugin in-tree testing

Bug: Issue 12096
Change-Id: I6e564a44a694d7739e33c79892fdfe13cbd86a10
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 230b39e..bf939f9 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -69,10 +69,11 @@
   ./tools/eclipse/project.py
 ```
 
-To execute the tests run:
+To execute the tests run either one of:
 
 ```
-  bazel test plugins/quota:quota_tests
+  bazel test --test_tag_filters=@PLUGIN@ //...
+  bazel test plugins/@PLUGIN@:@PLUGIN@_tests
 ```