Add how-to-make-thread-safe-calls.md & Update Layout with margin/padding (#1119)

* Update with margin/padding

* add how-to-make-thread-safe-calls

* reverse property mentions

dotnet-desktop-guide/net/winforms/controls/overview.md

@@ -1,7 +1,7 @@
 ---
 title: "Overview of Using Controls"
 description: Learn about how controls are used in Windows Forms for .NET. Controls are reusable components that provide functionality to the user. Many ready-to-use controls are provided. You can also make new controls.
-ms.date: 10/26/2020
+ms.date: 07/21/2021
 ms.topic: overview
 dev_langs: 
   - "csharp"
@@ -27,15 +27,28 @@ The position a control appears on a parent is determined by the value of the <xr
 
 Besides manual positioning and sizing, various container controls are provided that help with automatic placement of controls.
 
-For more information, see [Position and layout of controls](layout.md).
-<!-- TODO
+For more information, see [Position and layout of controls](layout.md) and [How to dock and anchor controls](how-to-dock-and-anchor.md).
 
 ## Control events
 
--->
+Controls provide a set of common events through the base class: <xref:System.Windows.Forms.Control>. Not every control responds to every event. For example, the <xref:System.Windows.Forms.Label> control doesn't respond to keyboard input, so the <xref:System.Windows.Forms.Control.PreviewKeyDown?displayProperty=nameWithType> event isn't raised. Most shared events fall under these categories:
+
+- Mouse events
+- Keyboard events
+- Property changed events
+- Other events
+
+For more information, see [Control events](events.md) and [How to handle a control event](how-to-add-an-event-handler.md).
+
+## Control accessibility
+
+Windows Forms has accessibility support for screen readers and voice input utilities for verbal commands. However, you must design your UI with accessibility in mind. Windows Forms controls expose various properties to handle accessibility. For more information about these properties, see [Providing Accessibility Information for Controls](provide-accessibility-information.md).
 
 ## See also
 
 - [Position and layout of controls](layout.md)
 - [Label control overview](labels.md)
-- [Add a control to a form](how-to-add-to-a-form.md)
+- [Control events](events.md)
+- [Types of custom controls](custom.md)
+- [Painting and drawing on controls](custom-painting-drawing.md)
+- [Providing Accessibility Information for Controls](provide-accessibility-information.md)