Create mainpage.md

doxygen/mainpage.md

@@ -0,0 +1,10 @@
+# Welcome
+
+This documentation describes the API usage for the Azure Kinect Sensor SDK.
+
+For details about the Azure Kinect DK hardware and for more information about getting started with development please see https://azure.com/kinect.
+
+## API Languages
+
+The Azure Kinect Sensor SDK is primarily a C API. This documentation also covers the C++ wrapper. For the most detailed documentation of
+API behavior, see the documentation for the C functions that the C++ classes wrap.