Register Theme Support for Gutenberg Wide Images

functions.php

<?php
/**
 * Register Theme Support for Gutenberg Wide Images
 */
function enable_wide_images() {
  add_theme_support( 'align-wide' );
}
add_action( 'after_setup_theme', 'enable_wide_images' );

style.css

/* Support Full Width Elements */
.entry-content .alignfull {
    margin-left  : calc( -100vw / 2 + 100% / 2 );
    margin-right : calc( -100vw / 2 + 100% / 2 );
    max-width    : 100vw;
}

/* Support Wide Align Elements */
.entry-content .alignwide {
    margin-left  : -100px;
    margin-right : -100px;
    max-width    : 1024px;
}