message: docs: clarify documentation for dependency searching
diff: @@ -7,7 +7,7 @@ Building, Testing, and Installing ADIOS 2
  Always do a fresh build from scratch if your source is updated with considerable changes *e.g.* `git pull`
  -To build ADIOS 2, clone the repository and invoke the canonical CMake build sequence:
  +To build ADIOS v2.x, clone the repository and invoke the canonical CMake build sequence:
  .. code-block:: bash
  @@ -122,20 +122,26 @@ Example: Enable Fortran, disable Python bindings and ZeroMQ functionality
  Notes:
  - * The ``ADIOS2_USE_HDF5`` option requires the use of a matching serial or parallel version depending on whether ``ADIOS2_USE_MPI`` is enabled. Similary, enabling MPI and Python bindings require ``mpi4py``.
  - * Optional ROOT suffix to a dependency can guide ``cmake`` into finding a particular dependency:
  + To provide search paths to CMake for dependency searching:
  +
  + - Use a ``PackageName_ROOT`` variable to provide the location of a specific package.
  + - Add an install prefix to the ``CMAKE_PREFIX_PATH`` which is searched for all packages.
  + - Both the ``PackageName_ROOT`` and ``CMAKE_PREFIX_PATH`` can be used as either environment variables or CMake variables (passed via -D), where the CMake variable takes prescedence.
  .. code-block:: bash
  + # Several dependencies are installed under /opt/foo/bar and then a
  + # single dependency (HDF5 in this case) is installed in /opt/hdf5/1.12.0
  + $ export CMAKE_PREFIX_PATH=/opt/foo/bar
  $ cmake -DHDF5_ROOT=/opt/hdf5/1.12.0 ../ADIOS2
  -Example: the following configuration will build, test and install under /opt/adios2/2.4.0 an optimized (Release) version of ADIOS2.
  +Example: the following configuration will build, test and install under /opt/adios2/2.5.0 an optimized (Release) version of ADIOS2.
  .. code-block:: bash
  $ cd build
  - $ cmake -DADIOS2_USE_Fortran=ON -DCMAKE_INSTALL_PREFIX=/opt/adios2/2.4.0 -DCMAKE_BUILD_Type=Release ../ADIOS2
  + $ cmake -DADIOS2_USE_Fortran=ON -DCMAKE_INSTALL_PREFIX=/opt/adios2/2.5.0 -DCMAKE_BUILD_Type=Release ../ADIOS2
  $ make -j16
  $ ctest
  $ make install
  