add horizontal line inhtml code example
Example 1: horizontal line html
<!-- code -->
<hr>
<!-- code -->
Example 2: which is right or in html
<hr> <!-- it represents a horizontal line break, in HTML4.0 we use <hr>,
in XHTML1.0 we use <hr/>, in HTML5(which is the current version of
HTML) we can use both <hr> and <hr/>
-->