Docs: about --credentials

[ProximaNova]

Tested in Ubuntu: it fails to download files when the file's filename start with a hyphen (-).

Good software. I changed this issue from what I originally had since I think some other part of my script/command messed it up.

Docs: about --credentials
In the documentation it says "--credentials - Note that terminal history on your system may reveal your credentials to other users, and your credentials will be stored in a plaintext file in either $HOME/.ia or $HOME/.config/ia.ini". I checked those via "cat $HOME/.config/ia.ini" and "cat $HOME/.ia" in GNU/Linux. Both commands stated "No such file or directory".

Docs: more info on --credentials
In the docs, the following should maybe also be stated. "Terminal history is not recorded if the command starts with a space, so 'echo a' will be recorded and ' echo a' will not be recorded. Email and password can be passed to stdin via '--credentials $(cat email.txt) $(cat pass.txt)'."

Also, would be neat to have this ability: #8