Mention how to create a test alias that actually runs the test.

RELNOTES: None.
PiperOrigin-RevId: 215183319
diff --git a/src/main/java/com/google/devtools/build/lib/rules/Alias.java b/src/main/java/com/google/devtools/build/lib/rules/Alias.java
index 85e651a..ed8d164 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/Alias.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/Alias.java
@@ -104,7 +104,10 @@
 
   <ul>
     <li>
-      Tests are not run if their alias is mentioned on the command line
+      Tests are not run if their alias is mentioned on the command line. To define an alias
+      that runs the referenced test, use a <a href="#test_suite"><code>test_suite</code></a>
+      rule with a single target in its <a href="#test_suite.tests"><code>tests</code></a>
+      attribute.
     </li>
     <li>
       When defining environment groups, the aliases to <code>environment</code> rules are not