chore: add readme and changelog

Signed-off-by: Bart Jaskulski <bjaskulski@protonmail.com>

CHANGELOG.md

+# [1.0.0] - 2023-11-17
+
+## Added
+- Initial project release with basic configuration.

README.md

+# Common PHPStan configuration for WP Desk
+
+This meta-package contains PHPStan configuration for WP Desk projects. This includes dependent extensions like `szepeviktor/phpstan-wordpress`, and additional, default configuration like inclusion of WooCommerce stubs.
+
+## Installation
+
+```sh
+composer require wpdesk/phpstan-rules
+```
+
+## Usage
+
+After installation, you can simply use PHPStan in your project without the need to further configuration. Nevertheless, as project grows, it's worth to add even [the basic one](https://phpstan.org/config-reference).
+
+To run PHPStan, simply execute the following command (<path> is only required if not present in configuration file):
+
+```sh
+vendor/bin/phpstan analyse <path>
+```