IVGCVSW-3726 Doxygen touch-up

 * Doxygen comment touch-ups
 * Fixed markup in .dox files
 * Fixed stylesheet
 * Doxyfile changes
 * Added logo file
 * Added header file

Signed-off-by: Ryan OShea <Ryan.OShea2@arm.com>
Change-Id: I94c7f5a6923a0bbb5c6ed610f1f55d57e2bb8a49
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index 29a0d4e..9779958 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -17,7 +17,7 @@
 
 constexpr unsigned int MaxNumOfTensorDimensions = 5U;
 
-// The lowest performance data capture interval we support is 10 miliseconds.
+/// The lowest performance data capture interval we support is 10 miliseconds.
 constexpr unsigned int LOWEST_CAPTURE_PERIOD = 10000u;
 
 /// @enum Status enumeration
@@ -308,7 +308,7 @@
 
 namespace std
 {
-// make ProfilingGuid hashable
+/// make ProfilingGuid hashable
 template<>
 struct hash<armnn::profiling::ProfilingGuid>
 {
@@ -318,7 +318,7 @@
     }
 };
 
-// make ProfilingDynamicGuid hashable
+/// make ProfilingDynamicGuid hashable
 template<>
 struct hash<armnn::profiling::ProfilingDynamicGuid>
 {
@@ -328,7 +328,7 @@
     }
 };
 
-// make ProfilingStaticGuid hashable
+/// make ProfilingStaticGuid hashable
 template<>
 struct hash<armnn::profiling::ProfilingStaticGuid>
 {