eslint since v7 warns about deprecation of root config
Now, if you have eslint config in your project and global config,
you should define it as root config (loss or copy/paste all recommended rules - preferred way with saving rules relate to project)
or define extends key with file system dotted path! 🤦♂️
If you want to have shared rules for different projects and don't want hardcoding path to file with common rules, you should create your custom eslint plugin with your rules (may be based on other recommended rules).