Fix --debug-avoidance description.

Fixes c&p error in --debug-avoidance description.

main/main.cpp

@@ -459,7 +459,7 @@ void Main::print_help(const char *p_binary) {
 	OS::get_singleton()->print("  --debug-collisions                Show collision shapes when running the scene.\n");
 	OS::get_singleton()->print("  --debug-paths                     Show path lines when running the scene.\n");
 	OS::get_singleton()->print("  --debug-navigation                Show navigation polygons when running the scene.\n");
-	OS::get_singleton()->print("  --debug-avoidance                 Show navigation polygons when running the scene.\n");
+	OS::get_singleton()->print("  --debug-avoidance                 Show navigation avoidance debug visuals when running the scene.\n");
 	OS::get_singleton()->print("  --debug-stringnames               Print all StringName allocations to stdout when the engine quits.\n");
 #endif
 	OS::get_singleton()->print("  --frame-delay <ms>                Simulate high CPU load (delay each frame by <ms> milliseconds).\n");