small improvement to types doc

include/ua_types.h

@@ -12,6 +12,8 @@ extern "C" {
 #include "ua_config.h"
 #include "ua_constants.h"
 
+#define UA_BUILTIN_TYPES_COUNT 25U
+
 /**
  * .. _types:
  *
@@ -20,7 +22,7 @@ extern "C" {
  *
  * The OPC UA protocol defines 25 builtin data types and three ways of combining
  * them into higher-order types: arrays, structures and unions. In open62541,
- * the builtin data types are defined manually. All other data types are
+ * only the builtin data types are defined manually. All other data types are
  * generated from standard XML definitions. Their exact definitions can be
  * looked up at https://opcfoundation.org/UA/schemas/Opc.Ua.Types.bsd.xml.
  *
@@ -29,11 +31,8 @@ extern "C" {
  * implementation details.
  *
  * Builtin Types
- * ------------- */
-
-#define UA_BUILTIN_TYPES_COUNT 25U
-
-/**
+ * -------------
+ *
  * Boolean
  * ^^^^^^^
  * A two-state logical value (true or false). */
@@ -166,7 +165,7 @@ UA_Boolean UA_EXPORT UA_String_equal(const UA_String *s1, const UA_String *s2);
 UA_EXPORT extern const UA_String UA_STRING_NULL;
 
 /**
- * ``UA_STRING`` returns a string pointing to the preallocated char-array.
+ * ``UA_STRING`` returns a string pointing to the original char-array.
  * ``UA_STRING_ALLOC`` is shorthand for ``UA_String_fromChars`` and makes a copy
  * of the char-array. */
 static UA_INLINE UA_String