.eslintrc.json

{
  "root": true,
  "ignorePatterns": ["projects/**/*"],
  "overrides": [
    {
      "files": ["*.ts"],
      "parserOptions": {
        "project": ["tsconfig.json"],
        "createDefaultProgram": true
      },
      "plugins": ["prefer-arrow", "unused-imports"],
      "extends": [
        "eslint:recommended",
        "plugin:@typescript-eslint/recommended",
        "plugin:@angular-eslint/recommended",
        "plugin:@angular-eslint/template/process-inline-templates",
        "prettier"
      ],
      "rules": {
        "@angular-eslint/directive-selector": [
          "error",
          {
            "type": "attribute",
            "prefix": "app",
            "style": "camelCase"
          }
        ],
        "@angular-eslint/no-output-on-prefix": 0,
        "@typescript-eslint/no-unused-vars": "off",
        "unused-imports/no-unused-imports": "error",
        "unused-imports/no-unused-vars": ["error", {"args": "none"}]
      }
    },
    {
      "files": ["*.html"],
      "extends": ["plugin:@angular-eslint/template/recommended", "prettier"],
      "rules": {}
    }
  ]
}

For the code to work several libraries need to be installed:

core - eslint + typescript

npm i --save-dev eslint typescript @typescript-eslint/parser @typescript-eslint/eslint-plugin

eslint-angular

npm i --save-dev @angular-eslint/builder @angular-eslint/eslint-plugin @angular-eslint/eslint-plugin-template @angular-eslint/schematics @angular-eslint/template-parser

additional plugins

npm i --save-dev eslint-plugin-ban eslint-plugin-prefer-arrow eslint-plugin-unused-imports

prettier

npm i --save-dev prettier eslint-config-prettier