Minor docs tweaks

docs/user_guide/source/components/io.rst

@@ -196,7 +196,7 @@ A particular ``Engine`` type is set to the current ``IO`` component with the ``I
 Engine polymorphism is handled internally by the ``IO`` class, which allows subclassing future derived ``Engine`` types without changing the basic API.
 
 ``Engine`` objects are created in various modes.
-The available modes are ``adios2::Mode::Read``, ``adios2::Mode::Write``, ``adios2::Mode::Append``, ``adios2::Mode::Sync``, ``adios2::Mode::Deferred``, and ``adios2::Mode::Undefined``.
+The available modes are ``adios2::Mode::Read``, ``adios2::Mode::ReadRandomAccess``, ``adios2::Mode::ReadFlattenSteps``, ``adios2::Mode::Write``, ``adios2::Mode::Append``, ``adios2::Mode::Sync``, ``adios2::Mode::Deferred``, and ``adios2::Mode::Undefined``.
 
 
 .. code-block:: c++

docs/user_guide/source/tutorials/helloWorld.rst

@@ -86,14 +86,15 @@ Start editing the skeleton file `ADIOS2/examples/hello/helloWorld/hello-world_tu
 
   adios2::Engine reader = io.Open("hello-world-cpp.bp", adios2::Mode::Read);
   std::string greeting;
+  reader.BeginStep();
   reader.Get(varGreeting, greeting);
   reader.EndStep();
   reader.Close();
   return greeting;
 
 .. note::
 
-  The ``BeginStep`` and ``EndStep`` calls are required when **reading** one step and multiple steps. We will see in
+  In Mode::Read, the ``BeginStep`` and ``EndStep`` calls are required when **reading** one step and multiple steps. We will see in
   another tutorial how to read multiple steps. It's important to note that the ``BeginStep`` should be called **before**
   all ``Inquire*`` / ``Available*`` function calls.