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/y2022/actors/autonomous_actor.cc b/y2022/actors/autonomous_actor.cc
index 19e9edf..41f7e04 100644
--- a/y2022/actors/autonomous_actor.cc
+++ b/y2022/actors/autonomous_actor.cc
@@ -18,8 +18,7 @@
 DEFINE_bool(rapid_react_two, false,
             "If true, run the two ball rapid react autonomous mode");
 
-namespace y2022 {
-namespace actors {
+namespace y2022::actors {
 namespace {
 constexpr double kExtendIntakeGoal = -0.10;
 constexpr double kRetractIntakeGoal = 1.47;
@@ -491,5 +490,4 @@
   }
 }
 
-}  // namespace actors
-}  // namespace y2022
+}  // namespace y2022::actors