Add v4->v5 upgrade guide to the docs #85

	name: Tests

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]

	jobs:
	test:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	php-versions: ['8.0', '8.1', '8.2']
	kirby-versions: ['^3.5', '^4.0-beta.1']

	steps:
	- uses: actions/checkout@v2

	- name: Setup PHP
	uses: shivammathur/setup-php@v2
	with:
	php-version: ${{ matrix.php-versions }}

	- name: Validate composer.json and composer.lock
	run: composer validate --strict

	- name: Remove vendor directory
	run: rm -rf vendor

	- name: Cache Composer packages
	id: composer-cache
	uses: actions/cache@v2
	with:
	path: vendor
	key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
	restore-keys: \|
	${{ runner.os }}-php-

	- name: Install dependencies
	run: composer install --prefer-dist --no-progress --no-plugins

	- name: Install Kirby Version
	run: composer require -w getkirby/cms:${{ matrix.kirby-versions }}

	- name: Run test suite
	run: vendor/bin/phpunit

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