Upgrade guide

• 4.0 to 5.0
• 3.4 to 4.0
• 3.3 to 3.4
• 3.2 to 3.3
• 3.1 to 3.2
• 3.0 to 3.1
• 2.x to 3.x
• Bard 1 to 2

If you intend to upgrade Laravel itself, please refer to its upgrade guide.
You can also (semi-)automate the Laravel upgrade using Laravel Shift which is by far the most rad way to upgrade.