Update file paths for editor plugin source files

Author: Hephaistos847

engine_details/editor/introduction_to_editor_development.rst

@@ -46,13 +46,13 @@ Some important files in the editor are:
 
 - `editor/editor_node.cpp <https://github.com/godotengine/godot/blob/master/editor/editor_node.cpp>`__:
   Main editor initialization file. Effectively the "main scene" of the editor.
-- `editor/project_manager.cpp <https://github.com/godotengine/godot/blob/master/editor/project_manager.cpp>`__:
+- `editor/project_manager/project_manager.cpp <https://github.com/godotengine/godot/blob/master/editor/project_manager/project_manager.cpp>`__:
   Main Project Manager initialization file. Effectively the "main scene" of the Project Manager.
-- `editor/plugins/canvas_item_editor_plugin.cpp <https://github.com/godotengine/godot/blob/master/editor/plugins/canvas_item_editor_plugin.cpp>`__:
+- `editor/scene/canvas_item_editor_plugin.cpp <https://github.com/godotengine/godot/blob/master/editor/scene/canvas_item_editor_plugin.cpp>`__:
   The 2D editor viewport and related functionality (toolbar at the top, editing modes, overlaid helpers/panels, …).
-- `editor/plugins/node_3d_editor_plugin.cpp <https://github.com/godotengine/godot/blob/master/editor/plugins/node_3d_editor_plugin.cpp>`__:
+- `editor/scene/3d/node_3d_editor_plugin.cpp <https://github.com/godotengine/godot/blob/master/editor/scene/3d/node_3d_editor_plugin.cpp>`__:
   The 3D editor viewport and related functionality (toolbar at the top, editing modes, overlaid panels, …).
-- `editor/plugins/node_3d_editor_gizmos.cpp <https://github.com/godotengine/godot/blob/master/editor/plugins/node_3d_editor_gizmos.cpp>`__:
+- `editor/scene/3d/node_3d_editor_gizmos.cpp <https://github.com/godotengine/godot/blob/master/editor/scene/3d/node_3d_editor_gizmos.cpp>`__:
   Where the 3D editor gizmos are defined and drawn.
   This file doesn't have a 2D counterpart as 2D gizmos are drawn by the nodes themselves.
 
@@ -85,4 +85,4 @@ Development tips
 To iterate quickly on the editor, we recommend to set up a test project and
 :ref:`open it from the command line <doc_command_line_tutorial>` after compiling
 the editor. This way, you don't have to go through the Project Manager every
-time you start Godot.
+time you start Godot.