Added diff --cached aliases

diff --cached will show the diff of files I have already staged

git/git.zsh

@@ -5,6 +5,7 @@ alias gb='git branch'
 alias gl='git pull'
 alias gp='git push'
 alias gd='git diff'
+alias gdc='git diff --cached'
 alias gs='git s'
 alias gss='git stash save'
 alias gsp='git stash pop'

git/gitconfig.symlink

@@ -13,6 +13,8 @@
     lg = log --graph --pretty=oneline --abbrev-commit --decorate
     # show files that have changed between two branches (git dbr master..branch)
     dbr = diff --name-status
+    # show diff of cached files
+    gdc = diff --cached
 
     # stash shortcuts
     sp = stash pop