5.0.0: Major release

• Components: All template parts and some funtions are replaced with component structure
• Gutenberg: Include default style sheets
• Gutenberg: Add Group block
• Gutenberg: Force class names for all blocks
• Gutenberg: Limit alignment options and set default aligns
• Gutenberg: Add fix for Gutenberg bug that shows wide and full images as blurry
• Gutenberg: Add class to first and last block in page
• Gulp: Babel support for ES6 and React
• Gulp: Upgrade to Gulp 4
• Gulp: Upgrade all packages
• Gulp: Replace deprecated css-nano
• Menus: Include two-level navigation
• Menus: Improve a11y
• Menus: New mobile menu that opens in overlay
• Styles: flatter organization
• Styles: mixins for margins and heading levels