Lint for ES2020, update deprecated rules, update tooling (#9)

* Remove unused configs `es2009` and `es2015`

* Remove deprecated rule `no-catch-shadow`

* Ignore `npm pack` debris

* Fix `package.main` not being published, and also change main file to `index.js`

* Install `eslint-find-rules` and use it to find deprecated rules during `npm test`

* Fix duplicated `package.main`

* Narrow `package.engines` to LTS

* Add `package.keywords` `pa11y`, `eslint`, `javascript`, `es2020`

* Install `eslint-plugin-n` and update deprecated Node.js-related rules

* Remove anchor links because most don't work

* Remove deprecated rules `require-jsdoc`, `valid-jsdoc`, `no-return-await`

* `id-blacklist` → `id-denylist`

* `lines-around-directive` → `padding-line-between-statements`

* `no-new-object` → `no-object-constructor`

* Remove deprecated rules `newline-*-*`

* Start warning for `prefer-destructuring` (for objects only)

* Start warning for `no-multi-assign` and `no-inline-comments`

* Rename `es2017.js` to `es2020.js`

* Update readme to reflect that module can be imported, and remove mentions of previous levels

* Mention peer dependencies

* Describe how to test workflows locally

* Update lockfile

* Ignore folder `.vscode`

Author: danyalaytekin

.eslintrc.js

@@ -1,3 +1,3 @@
 'use strict';
 
-module.exports = require('./eslint/es2017');
+module.exports = require('./index');

.gitignore

@@ -1,2 +1,8 @@
+# npm debris
 node_modules
 npm-debug.log
+/package
+*.tgz
+
+# Editors
+.vscode

README.md

@@ -21,26 +21,21 @@ This library requires [Node.js] 18 or above.
 
 ## Usage
 
-To include these config files in your project, first install [ESLint] and this module, saving them to development dependencies. For example, using npm:
+To include these config files in your project, install this module as a development dependency. Using npm:
 
 ```sh
-npm install --save-dev eslint pa11y-lint-config
+npm install --save-dev pa11y-lint-config
 ```
 
+The logging will mention any further peer dependencies required.
+
 Now create the files `.eslintrc.js` and `.eslintignore` in your project root. The following command will create both files and populate them with sensible settings for a new Pa11y project:
 
 ```sh
 printf "coverage\n" > .eslintignore
-printf "'use strict';\n\nmodule.exports = require('pa11y-lint-config/eslint/es2017');\n" > .eslintrc.js
+printf "'use strict';\n\nmodule.exports = require('pa11y-lint-config');\n" > .eslintrc.js
 ```
 
-Two other standards can replace `es2017` above:
-
-1. `es2015`, for an ES2015/ES6 project, forgoing the use of more recent syntax additions such as `async`
-1. `es2009`, for an ES2009/ES5 project, such as an older client-side codebase
-
-A project which contains more than one standard, for example ES2017 for the server and ES2015 for the browser, can support each required standard by including a different config file in each relevant subdirectory.
-
 ## Contributing
 
 There are many ways to contribute to Pa11y Lint Config, we cover these in the [contributing guide](CONTRIBUTING.md) for this repo.
@@ -53,6 +48,34 @@ Please check that everything works by running the following before opening a <ab
 npm test
 ```
 
+### Testing the GitHub Actions workflows
+
+This project's GitHub Actions workflows can be tested locally using [nektos/act](https://github.com/nektos/act), which can be installed with Homebrew:
+
+```sh
+brew install act
+```
+
+To run the testing workflow locally:
+
+```sh
+act
+```
+
+To validate the testing workflow, without running it:
+
+```sh
+act --dryrun
+```
+
+To validate the publishing workflow:
+
+```sh
+act --dryrun release
+```
+
+Add `--verbose` to any `act` command for more output.
+
 ## Support
 
 When we release a new major version we will continue to support the previous major version for 6 months. This support will be limited to fixes for critical bugs and security issues.
@@ -63,7 +86,6 @@ Licensed under the [Lesser General Public License (LGPL-3.0)](LICENSE).<br/>
 Copyright &copy; 2023, Team Pa11y
 
 
-
 [eslint]: http://eslint.org/
 [issues]: https://github.com/pa11y/pa11y-lint-config/issues
 [node.js]: https://nodejs.org/