Generate output using Doxygen / Breathe (#598)

* Modify Doxygen config to pick up include directories recursively

* Add DeviceMem struct to API Reference guide

* Add classes that are used in Flash Attention kernel

* Add a reference and config for generating bibliography

Co-authored-by: Philip Maybank <Philip.Maybank@amd.com>

[ROCm/composable_kernel commit: e4bf6d422e]

docs/source/API_Reference_Guide.rst

@@ -1,11 +1,11 @@
 
-===================
+*******************
 API Reference Guide
-===================
+*******************
 
-------------
+=================
 Introduction
-------------
+=================
 
 This document contains details of the APIs for the Composable Kernel (CK) library and introduces some of the key design
 principles that are used to write new classes that extend CK functionality.
@@ -16,8 +16,37 @@ Using CK API
 
 This section describes how to use the CK library API.
 
------------------
+=================
 CK Datatypes
+=================
+
+-----------------
+DeviceMem
 -----------------
 
-[TODO]
+.. doxygenstruct:: DeviceMem
+
+---------------------------
+Kernels For Flashattention
+---------------------------
+
+The Flashattention algorithm is defined in :cite:t:`dao2022flashattention`.  This sections lists the classes that are
+used in the CK GPU implementation of Flashattention.
+
+**Gridwise classes**
+
+.. doxygenstruct:: ck::GridwiseBatchedGemmSoftmaxGemm_Xdl_CShuffle
+
+**Blockwise classes**
+
+.. doxygenstruct:: ck::ThreadGroupTensorSliceTransfer_v4r1
+
+.. doxygenstruct:: ck::BlockwiseGemmXdlops_v2
+
+.. doxygenstruct:: ck::BlockwiseSoftmax
+
+**Threadwise classes**
+
+.. doxygenstruct:: ck::ThreadwiseTensorSliceTransfer_StaticToStatic
+
+.. bibliography::