Adding new manual documentation for ATC version 2.0

doc/USER/atc/man_add_molecule.html

doc/USER/atc/man_add_species.html

doc/USER/atc/man_atom_weight.html

doc/USER/atc/man_atomic_charge.html

doc/USER/atc/man_boundary.html

doc/USER/atc/man_boundary_dynamics.html

doc/USER/atc/man_boundary_faceset.html

doc/USER/atc/man_consistent_fe_initialization.html

doc/USER/atc/man_control.html

doc/USER/atc/man_control_momentum.html

doc/USER/atc/man_control_thermal.html

...ER/atc/man_control_thermal_correction_max_iterations.html

doc/USER/atc/man_decomposition.html

doc/USER/atc/man_fe_md_boundary.html

doc/USER/atc/man_filter_type.html

doc/USER/atc/man_internal_atom_integrate.html

doc/USER/atc/man_internal_element_set.html

doc/USER/atc/man_kernel_function.html

doc/USER/atc/man_localized_lambda.html

doc/USER/atc/man_lumped_lambda_solve.html