From: Sohom <sohom.datta@learner.manipal.edu>

Added text explaining that the git rm --cached command
isn't analogous to the gitignore file and that the file
will need to be added to gitignore to prevent later
commits from adding the file back.

Signed-off-by: Sohom Datta <sohom.datta@learner.manipal.edu>

Submitted-As: https://lore.kernel.org/git/pull.862.git.git.1601888338644.gitgitgadget@gmail.com