docs: add install instructions and note about eslint as dependency

README.md

@@ -2,7 +2,21 @@
 
 A drop-in replacement for ESLint 9 featuring multithreaded parallel linting.
 
-**IMPORTANT:** Legacy eslintrc configuration is not supported.
+> **IMPORTANT:** Legacy `.eslintrc` configuration is not supported.
+
+## Installation
+
+```shell
+npm i --save-dev eslint-p
+```
+
+```shell
+yarn add --dev eslint-p
+```
+
+```shell
+pnpm add --save-dev eslint-p
+```
 
 ## Usage
 
@@ -23,7 +37,21 @@ Valid values for the `--concurrency` option are:
 * **`off`**:
   No multithreading, run like ESLint. This is not the same as `--concurrency=1`.
 
-Normally, a performance improvement will be only noticeable on systems with 4 or more CPUs.
+> Normally, a performance improvement **will be only noticeable on systems with 4 or more CPUs**.
+
+## `ESLint` is installed as a dependency
+
+This package has ESLint set as a dependency, so if you already have `eslint` installed, but with a different version than the one specified in the `package.json` of this package you might get inconsistent results between the CLI and the editor.
+
+To check the version of `ESLint` used by this package you can use:
+
+```shell
+npx eslint-p -v
+```
+
+To avoid inconsistencies, install the same `eslint` version used by this package or remove the `eslint` dependency from your `package.json`.
+
+[You can find more information on this PR](https://github.com/origin-1/eslint-p/pull/1).
 
 [npm badge]: https://img.shields.io/npm/v/eslint-p?logo=npm
 [npm URL]: https://www.npmjs.com/package/eslint-p