Code Injection for Ghost so that the external links open in new tab.

gistfile1.txt

<script>
	// By default, Ghost blogging platform opens external links in the existing tab. 
	// You may the change the behavior if it is not desired. 
	// The following code opens all external links in a new tab.
    $(document).ready(function() {
        // Create a regex with current location
        var regex = '/' + window.location.host + '/';
        regex = regex.replace(/\./g,'\\\.');
        var exp = new RegExp(regex);
        // Find all links
        $('a[href^=http]').each(function() {
            if(!exp.test(this.href)) {
                $(this).click(function(event) {
                    event.preventDefault();
                    event.stopPropagation();
                    window.open(this.href, '_blank'); 
                });
            }
        });
    });
</script>