Update documentation.yml with ISA parser page

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
diff --git a/_data/documentation.yml b/_data/documentation.yml
index 3ddf4b4..ae48ef9 100644
--- a/_data/documentation.yml
+++ b/_data/documentation.yml
@@ -192,7 +192,10 @@
         url: /documentation/general_docs/architecture_support/
 
       - title: ARM Implementation
-        url: /documentation/general_docs/architecture_support/arm_implementation
+        url: /documentation/general_docs/architecture_support/arm_implementation/
+
+      - title: ISA Parser
+        url: /documentation/general_docs/architecture_support/isa_parser/
 
       - title: X86 microop ISA
         url: /documentation/general_docs/architecture_support/x86_microop_isa/