Display if a file is ignored by git

[ariasuni]

Fix #431

Display a dimmed I on the second column (unstaged status) when the file is ignored by git. Documentation is slightly edited to reflect the change.

Ideally, the screenshot on the main page and the page on the git feature should be updated to reflect this change.

[ogham]

Again, this is great, thank you. (Especially the subtle but accurate Readme change, which I’m sure I would have forgotten.)

[ariasuni]

I though it would be more easily discoverable/understandable if it was precised in the command itself. 😄

[cdfuller]

Thank you very much!