[PL] Rename GroundwaterFlow to SteadyStateDiffusion VI.

- Rename documentation files and add docu.

Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/i_process_variables.md

-\ogs_missing_documentation

Documentation/ProjectFile/prj/processes/process/GROUNDWATER_FLOW/process_variables/t_process_variable.md

-\ogs_missing_documentation

Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/c_STEADY_STATE_DIFFUSION.md

+Steady state diffusion process described by a scalar, elliptic partial differential equation.

Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/i_process_variables.md

+The process variable for the steady state diffusion process.

Documentation/ProjectFile/prj/processes/process/STEADY_STATE_DIFFUSION/process_variables/t_process_variable.md

+The scalar process variable for the steady state diffusion process, for instance
+temperature or pressure.

ProcessLib/SteadyStateDiffusion/CreateSteadyStateDiffusion.cpp

@@ -57,14 +57,14 @@ std::unique_ptr<Process> createSteadyStateDiffusion(
 
     // Process variable.
 
-    //! \ogs_file_param{prj__processes__process__GROUNDWATER_FLOW__process_variables}
+    //! \ogs_file_param{prj__processes__process__STEADY_STATE_DIFFUSION__process_variables}
     auto const pv_config = config.getConfigSubtree("process_variables");
 
     std::vector<std::vector<std::reference_wrapper<ProcessVariable>>>
         process_variables;
     auto per_process_variables = findProcessVariables(
         variables, pv_config,
-        {//! \ogs_file_param_special{prj__processes__process__GROUNDWATER_FLOW__process_variables__process_variable}
+        {//! \ogs_file_param_special{prj__processes__process__STEADY_STATE_DIFFUSION__process_variables__process_variable}
          "process_variable"});
     process_variables.push_back(std::move(per_process_variables));
 

web/content/docs/tools/model-preparation/create-boundary-conditions-along-a-polyline/index.pandoc

@@ -12,7 +12,7 @@ author = "Thomas Fischer"
 
 The tool `CreateBoundaryConditionsAlongPolylines` searches for mesh nodes that are near to polylines and generates for each found node an OGS-5 boundary condition at a point.
 
-The user has to provide the input mesh `mesh` and the geometry `geometry` that must contain at least one polyline. Possible input formats for the mesh are the legacy OGS-5 mesh format or the vtu format. The geometry can be provided in the legacy OGS-5 gli format as well as in the gml format. The user can specify an environment via a search radius around the polyline. For all nodes within this environment boundary conditions are generated. Furthermore the type of the process the boundary condition is belonging to should be given. At the moment there are boundary condition output for LIQUID_FLOW (primary variable PRESSURE1) and GROUNDWATER_FLOW (primary variable HEAD) process avaible.
+The user has to provide the input mesh `mesh` and the geometry `geometry` that must contain at least one polyline. Possible input formats for the mesh are the legacy OGS-5 mesh format or the vtu format. The geometry can be provided in the legacy OGS-5 gli format as well as in the gml format. The user can specify an environment via a search radius around the polyline. For all nodes within this environment boundary conditions are generated. Furthermore the type of the process the boundary condition is belonging to should be given. At the moment there are boundary condition output for LIQUID_FLOW (primary variable PRESSURE1) and STEADY_STATE_DIFFUSION (primary variable HEAD) process avaible.
 
 The tool will output a OGS-5 boundary condition file (.bc) and a geometry file (.gli) containing the points the boundary conditions refer to. The original geometry will not be altered. Additional, it is possible to write the geometry in the gml format by setting the switch `gml` to 1.