Sage 8.3.0

• Setup organization (#1558)
• Remove redundancy with WAI-ARIA in HTML (#1557)
• Rename config.php to setup.php (#1556)
• Move init.php to config.php (#1555)
• Use Sass to style search form, remove search template (#1545)
• Remove Modernizr (#1541)
• Remove references to WP_ENV (#1554)
• Use WP core's HTML5 gallery markup (#1546)
• Use slash in handle names for theme CSS and JS (#1537)
• Add compatibility with WooCommerce Multilingual plugin (#1530)
• Remove ConditionalTagCheck class (#1494)
• Add search templates (#1459)
• Allow debugger statements in development JavaScript (#1487)