2.4.0-M1

⭐ New Features

• Upgrade documentation styling #1640

🔨 Dependency Upgrades

• Upgrade Reactor to Dysprosium-SR9 #1652
• Upgrade Spring Security to 5.3.3.RELEASE #1651
• Upgrade samples to Spring Boot 2.3.1.RELEASE #1650
• Upgrade Spring Framework to 5.3.0-M1 #1649
• Upgrade Spring Data to 2020.0.0-M1 #1648