core(config) : Improve config class PHPDoc

[kwizer15]

Documentation PHPDoc de la classe config

Description

Cette PR standardise la documentation PHPDoc de la classe config (config.class.php).
Aucun changement fonctionnel n'est effectué.

Points clés

• Documentation complète des classes et méthodes avec types stricts
• Documentation précise des types de retour
• Spécification des dépendances entre les composants via @see
• Respect des standards de documentation Jeedom

Suggested changelog entry

• Added standardized PHPDoc documentation for config class

Related issues/external references

https://github.com/jeedom/documentations/blob/89cf4578ad04b59abebe40217b6cfdf0dacc195e/fr_FR/dev/php/phpdoc.md
https://community.jeedom.com/t/aide-phpdoc-du-core/63287

Types of changes

• Bug fix
• New feature
• Breaking change
• Documentation improvement

PR checklist

• I have checked there is no other PR open for the same change
• I have read the contribution guidelines for this project
• I grant the project the right to include and distribute the code under the GNU
• I have added tests to cover my changes
• I have verified that the code complies with the projects coding standards
• [Required for new sniffs] I have added MD documentation for the sniff