diff --git a/README.md b/README.md
index 0dec44d..319d1ae 100644
--- a/README.md
+++ b/README.md
@@ -23,10 +23,10 @@ The package provides an ability to record performance profiles.
 
 ## Installation
 
-The package could be installed via composer:
+The package could be installed with [Composer](https://getcomposer.org):
 
 ```shell
-composer require --dev yiisoft/profiler
+composer require yiisoft/profiler
 ```
 
 If you use this package with [Yii Config](https://github.com/yiisoft/config) and there will be no `@runtime` alias in `yiisoft/aliases` configuration defined, application will throw "Invalid path alias" error.
@@ -51,9 +51,6 @@ return [
 ### Profiling
 
 ```php
-<?php
-require __DIR__ . '/vendor/autoload.php';
-
 use Psr\Log\NullLogger;
 use Yiisoft\Profiler\Profiler;
 use Yiisoft\Profiler\Target\LogTarget;
@@ -168,32 +165,12 @@ $profiler = getProfiler();
 $profiler->flush();
 ```
 
-## Testing
-
-### Unit testing
-
-The package is tested with [PHPUnit](https://phpunit.de/). To run tests:
-
-```shell
-./vendor/bin/phpunit
-```
-
-### Mutation testing
+## Documentation
 
-The package tests are checked with [Infection](https://infection.github.io/) mutation framework with
-[Infection Static Analysis Plugin](https://github.com/Roave/infection-static-analysis-plugin). To run it:
+- [Internals](docs/internals.md)
 
-```shell
-./vendor/bin/roave-infection-static-analysis-plugin
-```
-
-### Static analysis
-
-The code is statically analyzed with [Psalm](https://psalm.dev/). To run static analysis:
-
-```shell
-./vendor/bin/psalm
-```
+If you need help or have a question, the [Yii Forum](https://forum.yiiframework.com/c/yii-3-0/63) is a good place for that.
+You may also check out other [Yii Community Resources](https://www.yiiframework.com/community).
 
 ## License
 
diff --git a/composer.json b/composer.json
index c60d167..88e16e6 100644
--- a/composer.json
+++ b/composer.json
@@ -63,4 +63,4 @@
         "test": "phpunit --testdox --no-interaction",
         "test-watch": "phpunit-watcher watch"
     }
-}
+}
\ No newline at end of file
diff --git a/docs/internals.md b/docs/internals.md
new file mode 100644
index 0000000..8dc4049
--- /dev/null
+++ b/docs/internals.md
@@ -0,0 +1,45 @@
+# Internals
+
+## Unit testing
+
+The package is tested with [PHPUnit](https://phpunit.de/). To run tests:
+
+```shell
+./vendor/bin/phpunit
+```
+
+## Mutation testing
+
+The package tests are checked with [Infection](https://infection.github.io/) mutation framework with
+[Infection Static Analysis Plugin](https://github.com/Roave/infection-static-analysis-plugin). To run it:
+
+```shell
+./vendor/bin/roave-infection-static-analysis-plugin
+```
+
+## Static analysis
+
+The code is statically analyzed with [Psalm](https://psalm.dev/). To run static analysis:
+
+```shell
+./vendor/bin/psalm
+```
+
+## Rector
+
+Use [Rector](https://github.com/rectorphp/rector) to make codebase follow some specific rules or
+use either newest or any specific version of PHP:
+
+```shell
+./vendor/bin/rector
+```
+
+## Composer require checker
+
+This package uses [composer-require-checker](https://github.com/maglnet/ComposerRequireChecker) to check if all dependencies are correctly defined in `composer.json`.
+
+To run the checker, execute the following command:
+
+```shell
+./vendor/bin/composer-require-checker
+```