Add support for yang type descriptions

Change-Id: I1fd070fb975aa82b2d4c1aa4165c5ab0153ff49f
diff --git a/src/leaf_data_type.hpp b/src/leaf_data_type.hpp
index 98cb12e..35a2961 100644
--- a/src/leaf_data_type.hpp
+++ b/src/leaf_data_type.hpp
@@ -105,9 +105,12 @@
     std::vector<TypeInfo> m_unionTypes;
 };
 struct TypeInfo {
-    TypeInfo(const yang::LeafDataType& type, const std::optional<std::string> units = std::nullopt);
+    TypeInfo(const yang::LeafDataType& type,
+            const std::optional<std::string> units = std::nullopt,
+            const std::optional<std::string> description = std::nullopt);
     bool operator==(const TypeInfo& other) const;
     yang::LeafDataType m_type;
     std::optional<std::string> m_units;
+    std::optional<std::string> m_description;
 };
 }