IVGCVSW-5348 Update Doxygen Docu

* update release version in Doxyfile

Signed-off-by: James Ward <james.ward@arm.com>
Change-Id: Iaaf06059eeba69b66b5ab211692a84c83ace9bb3
diff --git a/docs/Doxyfile b/docs/Doxyfile
index 7d20d0a..0c0b3e0 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -61,7 +61,7 @@
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 20.08
+PROJECT_NUMBER         = 20.11
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a