virtual display: compile example ok, not debug yet

Signed-off-by: fufesou <shuanglongchen@yeah.net>

libs/virtual_display/README.md

@@ -0,0 +1,32 @@
+# virtual display
+
+Virtual display may be used on computers that do not have a monitor.
+
+[Development reference](https://github.com/pavlobu/deskreen/discussions/86)
+
+## windows
+
+### win10
+
+Win10 provides [Indirect Display Driver Model](https://msdn.microsoft.com/en-us/library/windows/hardware/mt761968(v=vs.85).aspx).
+
+This lib use [this project](https://github.com/fufesou/RustDeskIddDriver) as the driver.
+
+
+**NOTE**: Versions before Win10 1607. Try follow [this method](https://github.com/fanxiushu/xdisp_virt/tree/master/indirect_display).
+
+
+#### tested platforms
+
+- [x] 19041
+
+
+### win7
+
+TODO
+
+[WDDM](https://docs.microsoft.com/en-us/windows-hardware/drivers/display/windows-vista-display-driver-model-design-guide).
+
+## X11
+
+## OSX