SWDEV-428554 - Standardize HIP Documentation

Relates to https://github.com/RadeonOpenCompute/rocm-docs-core/issues/330

Change-Id: I87468935a1aefa60158b8c07e3911845b3e8da36

docs/doxygen/mainpage.md

@@ -0,0 +1,33 @@
+# HIP Runtime API Reference {#mainpage}
+
+This is the full HIP Runtime API reference. The API is organized into
+[modules](modules.html) based on functionality.
+
+## List of Modules
+- @ref GlobalDefs
+- @ref Driver
+- @ref Device
+- @ref Execution
+- @ref Error
+- @ref Stream
+- @ref StreamM
+- @ref Event
+- @ref Memory
+  - @ref External
+  - @ref MemoryM
+  - @ref StreamO
+- @ref PeerToPeer
+- @ref Context
+  - @ref ContextD
+- @ref Module
+- @ref Occupancy
+- @ref Profiler
+- @ref Clang
+- @ref Texture
+  - @ref TextureD
+- @ref Runtime
+- @ref Callback
+- @ref Graph
+- @ref Virtual
+- @ref GL
+- @ref Surface