[Feature request] Only select files in staging area when doing Ctrl + up / down arrow

[fterrani]

When using the up and down arrow keys in the Unstaged / Staged area, one can select either a file or a folder. While I can understand the interest of selecting a folder of files to stage or unstage, this use case is not very frequent for me.

I tend to commit regularly and work file after file and in big projects. And when reviewing changes, I find it annoying to press the up and down arrow a varying number of time (once or twice or three times etc.) depending on the folder structure.

I would find it very handy to have a keyboard shortcut to only select files, e.g. Ctrl + up would select the first file above current selection, and Ctrl + down would do the same but select the first file below.

(By the way, congratulations for this awesome software :) )