This git hook appends "[ci skip]" to your commit message if the readme file is the only thing being touched. Read more about it here - http://about.travis-ci.org/docs/user/how-to-skip-a-build/

prepare-commit-msg

#!/usr/bin/env bash

# a list of all files that are changing with this commit
FILES_CHANGING=$(git diff --cached --name-only --diff-filter=ACM)

# if there is only one file changing
if [ $(echo "$FILES_CHANGING" | wc -l) -eq 1 ]; then
  
  # and that file is a readme
  README_CHANGING=$($FILES_CHANGING | grep -Ei "readme(.md|.txt)?$")

  if [ -n $README_CHANGING ]; then
    
    # append it to $1 - the file containing the commit message
    echo " [ci skip]" >> $1
  
  fi

fi

I found this hook very use full, tire of doing it by hand. I found an error:

README_CHANGING=$($FILES_CHANGING | grep -Ei "readme(.md|.txt)?$")

should be

README_CHANGING=$(echo $FILES_CHANGING | grep -Ei "readme(.md|.txt)?$")

This is the error I get when committing without the fix:

.git/hooks/prepare-commit-msg: line 12: README.md: command not found