fix spring doc page update

doc/src/fix_spring.txt

examples/USER/misc/basal/in.basal

src/atom_vec_atomic.cpp

src/atom_vec_body.cpp

src/atom_vec_charge.cpp

src/atom_vec_ellipsoid.cpp

src/atom_vec_hybrid.cpp

src/atom_vec_line.cpp

src/atom_vec_sphere.cpp

src/atom_vec_tri.cpp

src/comm_brick.cpp

src/domain.cpp

src/domain.h

src/math_extra.h

src/npair.cpp

src/region.cpp