Add 'git addnw' command

gitconfig

@@ -12,6 +12,7 @@
     tree = log --graph --oneline --all --full-history --decorate
     lg = log --graph --decorate --all --full-history --date=relative \
         --format=format:'%C(bold blue)%h%Creset %C(dim bold green)%<(14)%ad%Creset %C(dim white)%an%Creset  %s%C(bold yellow)%d%Creset'
+    addnw = !sh -c 'git diff -U0 -w --no-color "$@" | git apply --cached --ignore-whitespace --unidiff-zero -'
 
 [log]
     abbrevCommit = true