Use 4.0 method of connecting to and emitting signals (#6311)

Change docs to use the new method of connecting and emitting signals

getting_started/step_by_step/signals.rst

@@ -258,10 +258,10 @@ Click the script icon next to Sprite2D to jump back to the scripting workspace.
 We need to do two operations to connect the nodes via code:
 
 1. Get a reference to the Timer from the Sprite2D.
-2. Call the Timer's ``connect()`` method.
+2. Call the ``connect()`` method on the Timer's "timeout" signal.
 
 .. note:: To connect to a signal via code, you need to call the ``connect()``
-          method of the node you want to listen to. In this case, we want to
+          method of the signal you want to listen to. In this case, we want to
           listen to the Timer's "timeout" signal.
 
 We want to connect the signal when the scene is instantiated, and we can do that
@@ -439,7 +439,7 @@ you can connect to them like any other.
 
 .. image:: img/signals_17_custom_signal.png
 
-To emit a signal in your scripts, call ``emit_signal()``.
+To emit a signal in your scripts, call ``emit()`` on the signal.
 
 .. tabs::
  .. code-tab:: gdscript GDScript
@@ -447,7 +447,7 @@ To emit a signal in your scripts, call ``emit_signal()``.
     func take_damage(amount):
         health -= amount
         if health <= 0:
-            emit_signal("health_depleted")
+            health_depleted.emit()
 
  .. code-tab:: csharp C#
 
@@ -493,7 +493,7 @@ names between parentheses:
     correct values.
 
 To emit values along with the signal, add them as extra arguments to the
-``emit_signal()`` function:
+``emit()`` function:
 
 .. tabs::
  .. code-tab:: gdscript GDScript
@@ -501,7 +501,7 @@ To emit values along with the signal, add them as extra arguments to the
     func take_damage(amount):
         var old_health = health
         health -= amount
-        emit_signal("health_changed", old_health, health)
+        health_changed.emit(old_health, health)
 
  .. code-tab:: csharp C#