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]

library/include/ck/library/utility/device_memory.hpp

@@ -14,6 +14,10 @@ __global__ void set_buffer_value(T* p, T x, uint64_t buffer_element_size)
     }
 }
 
+/**
+ * @brief Container for storing data in GPU device memory
+ *
+ */
 struct DeviceMem
 {
     DeviceMem() = delete;