Add codecov config #465

Job	Run time
PHP-Linter (8.5) / linter	20s
Linter / yaml-linter	4s
PHP-Linter (8.4) / linter	12s
PHP-Linter (8.3) / linter	10s
Linter / json-linter	30s
Linter / style-linter	0s
Linter / ecmascript-linter	-1s
Unit tests, PHP ${{ matrix.php-versions }}, ${{ matrix.operating-system }}	0s
Unit tests, PHP ${{ matrix.php-versions }}, ${{ matrix.operating-system }}	0s
Security checks	0s
Code coverage	0s
Quality control	0s
Cleanup artifacts	0s
	1m 15s

Provide feedback