Update api.md

docs/api.md

@@ -86,6 +86,37 @@ Returns the absolute path to L'Math's plugin folder
 
 ## Frontend
 
+### api.getWindow() (`window`)
+Returns the vanilla JS `window` object.
+### api.getDocument() (`document`)
+Returns the vanilla JS `window.document` object.
+### api.getJQuery() (`jQuery`)
+Returns the jQuery (`$`) object of the window.
+
+### api.gui
+All returned elements are **plain DOM objects**, not jQuery objects.
+
+#### gui.getEditor()
+Returns the main ContentEditable editor area (`#_editor_area`) 
+#### gui.getSidebar()
+Returns the left-hand side sidebar (`#_work_tabs`) 
+#### gui.getToolbox()
+Returns the main top toolbar (`#_toolbox`) 
+#### gui.getTextToolbar()
+Returns the text toolbar (`#_bottom_row`) 
+#### gui.getCalc()
+Returns the T'Calc addon calculator window (`#_minicalc`)
+#### gui.getImageToolbox()
+Returns the floating image toolbox (`#_image_editor`)
+#### gui.getSpinner()
+Returns the loading spinner
+#### gui.getSpinnerDimmer()
+Returns the loading spinner dimmer
+#### gui.getDialogContainer()
+Returns the special dialog container (that contains e.g. the welcome and settings dialogs)
+
+
+
 ### events
 * `worksheetLoading`
     * Called when a worksheet is being loaded