Update PadFirstAxis.jl
Update PadFirstAxis.jl

shortened the syntax
fercarozzi/Seismic.jl,fercarozzi/myseismicjulia,WneleiGao/Seismic.jl,SeismicJulia/Seismic.jl,JuliaPackageMirrors/Seismic.jl,juanisabbione/Seismic.jl