query on git submodule (ignore)

Hello,

I am new to this community ,so please ignore if I am asking anything silly.

Case : Today when I built my submodule , and did a git status , it shows as modified.

After reading certain suggestions on web i found out that i can ignore that adding a line in .gitmodules

But, I had to add that line manually ( which could be errorprone because of typos )

Question:
    1. Is it feasible to build a feature like :
                   git submodule "zlib" ignore dirty ( which will
ignore submodule zlib when its built and dirty  as it has new files in
its directory)

If this feature is feasible , how do i know if its developed ( awaiting merge ) or can I build the patch ?

Regards, Prashant