Merge pull request #1358 from edubxb/git-diff-staged-alias

New git alias for `git diff --staged`

aliases/available/git.aliases.bash

@@ -36,6 +36,7 @@ alias gr='git remote'
 alias grv='git remote -v'
 alias gra='git remote add'
 alias gd='git diff'
+alias gds='git diff --staged'
 alias gdv='git diff -w "$@" | vim -R -'
 alias gc='git commit -v'
 alias gca='git commit -v -a'