[doc] Add <meshes>/<mesh> tags descriptions.

Applications/ApplicationsLib/ProjectData.cpp

@@ -122,6 +122,11 @@ std::unique_ptr<MeshLib::Mesh> readSingleMesh(
                   mesh_file.c_str());
     }
 
+#ifdef DOXYGEN_DOCU_ONLY
+    //! \ogs_file_attr{prj__meshes__mesh__axially_symmetric}
+    mesh_config_parameter.getConfigAttributeOptional<bool>("axially_symmetric");
+#endif  // DOXYGEN_DOCU_ONLY
+
     if (auto const axially_symmetric =
             //! \ogs_file_attr{prj__mesh__axially_symmetric}
         mesh_config_parameter.getConfigAttributeOptional<bool>(

Documentation/ProjectFile/prj/meshes/i_meshes.md

+External mesh file names for the process variables and the boundary conditions.

Documentation/ProjectFile/prj/meshes/mesh/a_axially_symmetric.md

+\ogs_missing_documentation

Documentation/ProjectFile/prj/meshes/mesh/i_mesh.md

+Information about input mesh.

Documentation/ProjectFile/prj/process_variables/process_variable/boundary_conditions/boundary_condition/NonuniformDirichlet/t_mesh.md

-Path to the surface mesh vtu file.
-
-The surface mesh must contain a nodal integer-valued field (unsigned 64bit)
-named \c OriginalSubsurfaceNodeIDs. That field establishes the mapping between
-the nodes of the surface mesh to some notes in the bulk mesh.
-\warning It is not checked if the surface mesh and the bulk mesh correspond to each
-other; in particular it is not checked if surface and bulk nodes coincide and if
-surface elements coincide with the faces of bulk elements.

Documentation/ProjectFile/prj/process_variables/process_variable/boundary_conditions/boundary_condition/NonuniformNeumann/t_mesh.md

-Path to the surface mesh vtu file.
-
-The surface mesh must contain a nodal integer-valued field (unsigned 64bit)
-named \c OriginalSubsurfaceNodeIDs. That field establishes the mapping between
-the nodes of the surface mesh to some notes in the bulk mesh.
-\warning It is not checked if the surface mesh and the bulk mesh correspond to each
-other; in particular it is not checked if surface and bulk nodes coincide and if
-surface elements coincide with the faces of bulk elements.

Documentation/ProjectFile/prj/process_variables/process_variable/boundary_conditions/boundary_condition/t_mesh.md

+Name of the surface mesh where the boundary condition will be defined.
+
+The surface mesh must contain a nodal integer-valued field (unsigned 64bit)
+named \c bulk_node_ids, and a cell field named \c bulk_element_ids. These fields
+establish the mapping between the nodes of the surface mesh to the nodes in the
+bulk mesh.
+
+\warning It is not checked if the surface mesh and the bulk mesh
+correspond to each other; in particular it is not checked if surface and bulk
+nodes coincide and if surface elements coincide with the faces of bulk elements.

Documentation/ProjectFile/prj/process_variables/process_variable/source_terms/source_term/t_mesh.md

+Name of the mesh where the source term will be applied.
+
+The surface mesh must contain a nodal integer-valued field (unsigned 64bit)
+named \c bulk_node_ids, and a cell field named \c bulk_element_ids. These fields
+establish the mapping between the nodes of the surface mesh to the nodes in the
+bulk mesh.
+
+\warning It is not checked if the surface mesh and the bulk mesh
+correspond to each other; in particular it is not checked if surface and bulk
+nodes coincide and if surface elements coincide with the faces of bulk elements.

Documentation/ProjectFile/prj/process_variables/process_variable/t_mesh.md

+A mesh name for the process variable's domain of definition.

ProcessLib/ProcessVariable.cpp

@@ -30,6 +30,12 @@ MeshLib::Mesh const& findMeshInConfig(
     //
     std::string mesh_name;  // Either given directly in <mesh> or constructed
                             // from <geometrical_set>_<geometry>.
+
+#ifdef DOXYGEN_DOCU_ONLY
+    //! \ogs_file_param{prj__process_variables__process_variable__source_terms__source_term__mesh}
+    config.getConfigParameterOptional<std::string>("mesh");
+#endif  // DOXYGEN_DOCU_ONLY
+
     auto optional_mesh_name =
         //! \ogs_file_param{prj__process_variables__process_variable__boundary_conditions__boundary_condition__mesh}
         config.getConfigParameterOptional<std::string>("mesh");
@@ -40,6 +46,14 @@ MeshLib::Mesh const& findMeshInConfig(
     else
     {
         // Looking for the mesh created before for the given geometry.
+
+#ifdef DOXYGEN_DOCU_ONLY
+        //! \ogs_file_param{prj__process_variables__process_variable__source_terms__source_term__geometrical_set}
+        config.getConfigParameterOptional<std::string>("geometrical_set");
+        //! \ogs_file_param{prj__process_variables__process_variable__source_terms__source_term__geometry}
+        config.getConfigParameter<std::string>("geometry");
+#endif  // DOXYGEN_DOCU_ONLY
+
         auto const geometrical_set_name =
             //! \ogs_file_param{prj__process_variables__process_variable__boundary_conditions__boundary_condition__geometrical_set}
             config.getConfigParameter<std::string>("geometrical_set");