Fix duplicate shortcut in TileMap Editor

This pull request fixes an issue where the paint and erase tools in the TileMap editor had the same shortcut (E). The erase tool having "E" be its shortcut makes more sense than the paint tool having that be its shortcut. So I changed the paint tool's shortcut to be "D" since nothing else uses it and it's short for "draw", it's also right next to "S" on the keyboard which happens to be the selection tool.

editor/plugins/tiles/tile_map_editor.cpp

@@ -1756,7 +1756,7 @@ TileMapEditorTilesPlugin::TileMapEditorTilesPlugin() {
 	paint_tool_button->set_flat(true);
 	paint_tool_button->set_toggle_mode(true);
 	paint_tool_button->set_button_group(tool_buttons_group);
-	paint_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/paint_tool", "Paint", KEY_E));
+	paint_tool_button->set_shortcut(ED_SHORTCUT("tiles_editor/paint_tool", "Paint", KEY_D));
 	paint_tool_button->connect("pressed", callable_mp(this, &TileMapEditorTilesPlugin::_update_toolbar));
 	tilemap_tiles_tools_buttons->add_child(paint_tool_button);