Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/y2024_defense/joystick_reader.cc b/y2024_defense/joystick_reader.cc
index 8c3115b..5eeb864 100644
--- a/y2024_defense/joystick_reader.cc
+++ b/y2024_defense/joystick_reader.cc
@@ -23,9 +23,7 @@
 
 using Side = frc971::control_loops::drivetrain::RobotSide;
 
-namespace y2024_defense {
-namespace input {
-namespace joysticks {
+namespace y2024_defense::input::joysticks {
 
 class Reader : public ::frc971::input::ActionJoystickInput {
  public:
@@ -46,9 +44,7 @@
   }
 };
 
-}  // namespace joysticks
-}  // namespace input
-}  // namespace y2024_defense
+}  // namespace y2024_defense::input::joysticks
 
 int main(int argc, char **argv) {
   ::aos::InitGoogle(&argc, &argv);