change tooltip title bootstrap 4 code example
Example: how to add heading and paragraph in bootstrap tooltip
<a href="#" rel="tooltip" title="Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas bibendum ac felis id commodo. Etiam mauris purus, fringilla id tempus in, mollis vel orci. Duis ultricies at erat eget iaculis.">Hover here please</a>