ci: Ensure that eslint runs on all frontend code (no-changelog) (#4602)

* ensure that eslint runs on all frontend code

* remove tslint from `design-system`

* enable prettier and eslint-prettier for `design-system`

* Delete tslint.json

* use a single editorconfig for the repo

* enable prettier for all code in `design-system`

* more linting fixes on design-system

* ignore coverage for git and prettier

* lintfix on editor-ui

packages/design-system/.storybook/main.js

@@ -14,7 +14,7 @@ module.exports = {
 				postcssLoaderOptions: {
 					implementation: require('postcss'),
 				},
-			}
+			},
 		},
 		'storybook-addon-designs',
 		'storybook-addon-themes',