diff --git a/README.md b/README.md
index 918bd95..a85ee4d 100644
--- a/README.md
+++ b/README.md
@@ -27,10 +27,10 @@ If too many requests are received from a user within the stated period of the ti
 
 ## Installation
 
-The package could be installed with composer:
+The package could be installed with [Composer](https://getcomposer.org):
 
 ```shell
-composer install yiisoft/rate-limiter
+composer require yiisoft/rate-limiter
 ```
 
 ## General usage
@@ -98,32 +98,12 @@ There are two ready to use counter storages available in the package:
 
 To use your own storage implement `Yiisoft\Yii\RateLimiter\Storage\StorageInterface`. 
 
-## Testing
+## Documentation
 
-### Unit testing
+- [Internals](docs/internals.md)
 
-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
-```
+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/UPGRADE.md b/UPGRADE.md
index e2af1f8..104557e 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -1,7 +1,6 @@
-# Upgrading Instructions for Yii Rate Limiter
+# Yii Rate Limiter Middleware Upgrading Instructions
 
-This file contains the upgrade notes for the Yii Rate Limiter.
-These notes highlight changes that could break your application when you upgrade it from one major version to another.
+This file contains notes that highlight changes that could break your application when you upgrade it from one major version to another.
 
 ## 2.0.0
 
diff --git a/docs/internals.md b/docs/internals.md
new file mode 100644
index 0000000..087a514
--- /dev/null
+++ b/docs/internals.md
@@ -0,0 +1,44 @@
+# 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
+```
+
+## Code style
+
+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
+```
+
+## Dependencies
+
+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
+```