code: function splitTextNode( textnode, regexp, replacement ) {
  		let text = textnode.nodeValue,
  			index = text.search( regexp ),
  			match = text.match( regexp ),
  			captured = [],
  			cursor;
  
  		if ( index < 0 || ! match.length ) {
  			return [ textnode ];
  		}
  
  		if ( index > 0 ) {
  			// capture left text node
  			captured.push( document.createTextNode( text.substr( 0, index ) ) );
  		}
  
  		// capture the replacement of the matched string
  		captured.push( parent.create( match[ 0 ].replace( regexp, replacement ) ) );
  
  		cursor = index + match[ 0 ].length;
  
  		if ( cursor < text.length ) {
  			// capture right text node
  			captured.push( document.createTextNode( text.substr( cursor ) ) );
  		}
  
  		return captured;
  	}
docs: Split a text node into an ordered list of siblings:
  - text node to the left of the match
  - the element replacing the match
  - text node to the right of the match
  
  We have to leave the text to the left and right of the match alone
  in order to prevent XSS
  
  @return array