subprocess.h: document name, executable name behavior

Change-Id: I628ba7b6fb93392209e575272c9ef1f3f5f31ba2
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>
diff --git a/aos/starter/subprocess.h b/aos/starter/subprocess.h
index 87479e8..99ad053 100644
--- a/aos/starter/subprocess.h
+++ b/aos/starter/subprocess.h
@@ -58,6 +58,10 @@
   Application(const aos::Application *application, aos::EventLoop *event_loop,
               std::function<void()> on_change);
 
+  // executable_name is the actual executable path.
+  // When sudo is not used, name is used as argv[0] when exec'ing
+  // executable_name. When sudo is used it's not possible to pass in a
+  // distinct argv[0].
   Application(std::string_view name, std::string_view executable_name,
               aos::EventLoop *event_loop, std::function<void()> on_change);