Delete unused ColumnSubheading

app/soapbox/features/ui/components/column_subheading.js

@@ -1,16 +0,0 @@
-import PropTypes from 'prop-types';
-import React from 'react';
-
-const ColumnSubheading = ({ text }) => {
-  return (
-    <div className='column-subheading'>
-      {text}
-    </div>
-  );
-};
-
-ColumnSubheading.propTypes = {
-  text: PropTypes.string.isRequired,
-};
-
-export default ColumnSubheading;