ESLint not working

[lars-reimann]

Describe the bug

ESLint is seemingly not properly configured anymore since the repo merge.

Tasks

• Move ESLint config files to top of repository
• Update config to disallow default exports. Default exports are a nuisance when renaming exported elements. The refactoring doesn't work properly since each user can provide his own name.
• Publish new config on NPM
• Use new config here
• Disable TYPESCRIPT_STANDARD linter in .mega-linter.yml