Added git alias dc - "diff --cached"

dotfiles/git-universe/gitconfig

@@ -10,3 +10,4 @@
     editor = vim
 [alias]
   gr = log --graph --full-history --all --color --pretty=tformat:"%x1b[31m%h%x09%x1b[32m%d%x1b[0m%x20%s%x1b[0m"
+  dc = diff --cached