message: Doc: use correct ref types for flatcc string creation.
  Some string definitions were typed as ns(Weapon_ref_t) while they should
  be flatbuffers_string_ref_t. Note that the former was also compiling &
  running correctly as both ref types boil down to the same underlying ref
  type.
diff: @@ -735,10 +735,10 @@ our `orc` Monster, lets create some `Weapon`s: a `Sword` and an `Axe`.
  </div>
  <div class="language-c">
  ~~~{.c}
  - ns(Weapon_ref_t) weapon_one_name = flatbuffers_string_create_str(B, "Sword");
  + flatbuffers_string_ref_t weapon_one_name = flatbuffers_string_create_str(B, "Sword");
  uint16_t weapon_one_damage = 3;
  - ns(Weapon_ref_t) weapon_two_name = flatbuffers_string_create_str(B, "Axe");
  + flatbuffers_string_ref_t weapon_two_name = flatbuffers_string_create_str(B, "Axe");
  uint16_t weapon_two_damage = 5;
  ns(Weapon_ref_t) sword = ns(Weapon_create(B, weapon_one_name, weapon_one_damage));
  