title: git command to add/stage modified files in folders only
body: <p>I've modified several files in a folder and subfolders. I could add the top folder recursively but then i have several subfolders that are untracked, so every time I do the recursive add to stage changes, I have to untrack the subfolders with <code>git rm -r --cached</code>. Is there a better way to just stage the modifications that show up in git status, without tracking already explicitly untracked files?</p>
  
  <p>meta-question: is it really a good idea that <code>git add</code> means two (or more) things? in this context, if the command to track files (<code>git add</code>) were not the same used for stage modifications (<code>git add</code>) then i would not have this problem in the first place</p>